permissions := strconv.Atoi(os.Getenv("filePermissions"));
fMode := os.FileMode(permissions)
os.chmod(filePath, fMode);
...
String permissionMask = System.getProperty("defaultFileMask");
Path filePath = userFile.toPath();
...
Set<PosixFilePermission> perms = PosixFilePermissions.fromString(permissionMask);
Files.setPosixFilePermissions(filePath, perms);
...
$rName = $_GET['publicReport'];
chmod("/home/". authenticateUser . "/public_html/" . rName,"0755");
...
publicReport
, such as "../../localuser/public_html/.htpasswd
", the application will make the specified file readable to the attacker.
...
$mask = $CONFIG_TXT['perms'];
chmod($filename,$mask);
...
permissions = os.getenv("filePermissions");
os.chmod(filePath, permissions);
...
...
rName = req['publicReport']
File.chmod("/home/#{authenticatedUser}/public_html/#{rName}", "0755")
...
publicReport
, such as "../../localuser/public_html/.htpasswd
", the application will make the specified file readable to the attacker.
...
mask = config_params['perms']
File.chmod(filename, mask)
...
services-config.xml
descriptor file specifies a "Logging" XML element to describe various aspects of logging. It looks like the following:
<logging>
<target class="flex.messaging.log.ConsoleTarget" level="Debug">
<properties>
<prefix>[BlazeDS]</prefix>
<includeDate>false</includeDate>
<includeTime>false</includeTime>
<includeLevel>false</includeLevel>
<includeCategory>false</includeCategory>
</properties>
<filters>
<pattern>Endpoint.*</pattern>
<pattern>Service.*</pattern>
<pattern>Configuration</pattern>
</filters>
</target>
</logging>
target
tag takes an optional attribute called level
, which indicates the log level. If the debug level is set to too detailed a level, your application may write sensitive data to the log file.sprintf()
, FormatMessageW()
, or syslog()
.snprintf()
.
int main(int argc, char **argv){
char buf[128];
...
snprintf(buf,128,argv[1]);
}
%x
, than the function takes as arguments to be formatted. (In this example, the function takes no arguments to be formatted.) By using the %n
formatting directive, the attacker may write to the stack, causing snprintf()
to write the number of bytes output thus far to the specified argument (rather than reading a value from the argument, which is the intended behavior). A sophisticated version of this attack will use four staggered writes to completely control the value of a pointer on the stack.
printf("%d %d %1$d %1$d\n", 5, 9);
5 9 5 5
Example 1
.syslog()
function is sometimes used as follows:
...
syslog(LOG_ERR, cmdBuf);
...
syslog()
is a format string, any formatting directives included in cmdBuf
are interpreted as described in Example 1
.syslog()
:
...
syslog(LOG_ERR, "%s", cmdBuf);
...
sprintf()
, FormatMessageW()
, syslog()
, NSLog
, or NSString.stringWithFormat
Example 1: The following code utilizes a command line argument as a format string in NSString.stringWithFormat:
.
int main(int argc, char **argv){
char buf[128];
...
[NSString stringWithFormat:argv[1], argv[2] ];
}
%x
, than the function takes as arguments to be formatted. (In this example, the function takes no arguments to be formatted.)
printf("%d %d %1$d %1$d\n", 5, 9);
5 9 5 5
Example 1
.syslog()
function is sometimes used as follows:
...
syslog(LOG_ERR, cmdBuf);
...
syslog()
is a format string, any formatting directives included in cmdBuf
are interpreted as described in Example 1
.syslog()
:Example 4: Apple core classes provide interesting avenues for exploiting format string vulnerabilities.
...
syslog(LOG_ERR, "%s", cmdBuf);
...
String.stringByAppendingFormat()
function is sometimes used as follows:
...
NSString test = @"Sample Text.";
test = [test stringByAppendingFormat:[MyClass
formatInput:inputControl.text]];
...
stringByAppendingFormat()
:
...
NSString test = @"Sample Text.";
test = [test stringByAppendingFormat:@"%@", [MyClass
formatInput:inputControl.text]];
...
strncpy()
, can cause vulnerabilities when used incorrectly. The combination of memory manipulation and mistaken assumptions about the size or makeup of a piece of data is the root cause of most buffer overflows.
void wrongNumberArgs(char *s, float f, int d) {
char buf[1024];
sprintf(buf, "Wrong number of %.512s");
}
strncpy()
, can cause vulnerabilities when used incorrectly. The combination of memory manipulation and mistaken assumptions about the size or makeup of a piece of data is the root cause of most buffer overflows.f
from a float using a %d
format specifier.
void ArgTypeMismatch(float f, int d, char *s, wchar *ws) {
char buf[1024];
sprintf(buf, "Wrong type of %d", f);
...
}
...
String lang = Request.Form["lang"];
WebClient client = new WebClient();
client.BaseAddress = url;
NameValueCollection myQueryStringCollection = new NameValueCollection();
myQueryStringCollection.Add("q", lang);
client.QueryString = myQueryStringCollection;
Stream data = client.OpenRead(url);
...
lang
such as en&poll_id=1
, and then the attacker may be able to change the poll_id
at will.
...
String lang = request.getParameter("lang");
GetMethod get = new GetMethod("http://www.example.com");
get.setQueryString("lang=" + lang + "&poll_id=" + poll_id);
get.execute();
...
lang
such as en&poll_id=1
, and then the attacker will be able to change the poll_id
at will.
<%
...
$id = $_GET["id"];
header("Location: http://www.host.com/election.php?poll_id=" . $id);
...
%>
name=alice
specified, but they've added an additional name=alice&
, and if this is being used on a server that takes the first occurrence, then this may impersonate alice
in order to get further information regarding her account.
...
encryptionKey = "".
...
...
var encryptionKey:String = "";
var key:ByteArray = Hex.toArray(Hex.fromString(encryptionKey));
...
var aes.ICipher = Crypto.getCipher("aes-cbc", key, padding);
...
...
char encryptionKey[] = "";
...
...
<cfset encryptionKey = "" />
<cfset encryptedMsg = encrypt(msg, encryptionKey, 'AES', 'Hex') />
...
...
key := []byte("");
block, err := aes.NewCipher(key)
...
...
private static String encryptionKey = "";
byte[] keyBytes = encryptionKey.getBytes();
SecretKeySpec key = new SecretKeySpec(keyBytes, "AES");
Cipher encryptCipher = Cipher.getInstance("AES");
encryptCipher.init(Cipher.ENCRYPT_MODE, key);
...
...
var crypto = require('crypto');
var encryptionKey = "";
var algorithm = 'aes-256-ctr';
var cipher = crypto.createCipher(algorithm, encryptionKey);
...
...
CCCrypt(kCCEncrypt,
kCCAlgorithmAES,
kCCOptionPKCS7Padding,
"",
0,
iv,
plaintext,
sizeof(plaintext),
ciphertext,
sizeof(ciphertext),
&numBytesEncrypted);
...
...
$encryption_key = '';
$filter = new Zend_Filter_Encrypt($encryption_key);
$filter->setVector('myIV');
$encrypted = $filter->filter('text_to_be_encrypted');
print $encrypted;
...
...
from Crypto.Ciphers import AES
cipher = AES.new("", AES.MODE_CFB, iv)
msg = iv + cipher.encrypt(b'Attack at dawn')
...
require 'openssl'
...
dk = OpenSSL::PKCS5::pbkdf2_hmac_sha1(password, salt, 100000, 0) # returns an empty string
...
...
CCCrypt(UInt32(kCCEncrypt),
UInt32(kCCAlgorithmAES128),
UInt32(kCCOptionPKCS7Padding),
"",
0,
iv,
plaintext,
plaintext.length,
ciphertext.mutableBytes,
ciphertext.length,
&numBytesEncrypted)
...
...
Dim encryptionKey As String
Set encryptionKey = ""
Dim AES As New System.Security.Cryptography.RijndaelManaged
On Error GoTo ErrorHandler
AES.Key = System.Text.Encoding.ASCII.GetBytes(encryptionKey)
...
Exit Sub
...
...
DATA: lo_hmac TYPE Ref To cl_abap_hmac,
Input_string type string.
CALL METHOD cl_abap_hmac=>get_instance
EXPORTING
if_algorithm = 'SHA3'
if_key = space
RECEIVING
ro_object = lo_hmac.
" update HMAC with input
lo_hmac->update( if_data = input_string ).
" finalise hmac
lo_digest->final( ).
...
Example 1
may run successfully, but anyone who has access to it will be able to figure out that it uses an empty HMAC key. After the program ships, there is likely no way to change the empty HMAC key unless the program is patched. A devious employee with access to this information could use it to compromise the HMAC function. Also, the code in Example 1
is vulnerable to forgery and key recovery attacks.
...
using (HMAC hmac = HMAC.Create("HMACSHA512"))
{
string hmacKey = "";
byte[] keyBytes = Encoding.ASCII.GetBytes(hmacKey);
hmac.Key = keyBytes;
...
}
...
Example 1
may run successfully, but anyone who has access to it will be able to figure out that it uses an empty HMAC key. After the program ships, there is likely no way to change the empty HMAC key unless the program is patched. A devious employee with access to this information could use it to compromise the HMAC function. Also, the code in Example 1
is vulnerable to forgery and key recovery attacks.
import "crypto/hmac"
...
hmac.New(md5.New, []byte(""))
...
Example 1
might run successfully, but anyone who has access to it can determine that it uses an empty HMAC key. After the program ships, there is no way to change the empty HMAC key unless the program is patched. A devious employee with access to this information could use it to compromise the HMAC function. Also, the code in Example 1
is vulnerable to forgery and key recovery attacks.
...
private static String hmacKey = "";
byte[] keyBytes = hmacKey.getBytes();
...
SecretKeySpec key = new SecretKeySpec(keyBytes, "SHA1");
Mac hmac = Mac.getInstance("HmacSHA1");
hmac.init(key);
...
Example 1
may run successfully, but anyone who has access to it will be able to figure out that it uses an empty HMAC key. After the program ships, there is likely no way to change the empty HMAC key unless the program is patched. A devious employee with access to this information could use it to compromise the HMAC function. Also, the code in Example 1
is vulnerable to forgery and key recovery attacks.
...
let hmacKey = "";
let hmac = crypto.createHmac("SHA256", hmacKey);
hmac.update(data);
...
Example 1
might run successfully, but anyone with access to it might figure out that it uses an empty HMAC key. After the program ships, there is likely no way to change the empty HMAC key unless the program is patched. A devious employee with access to this information could use it to compromise the HMAC function.
...
CCHmac(kCCHmacAlgSHA256, "", 0, plaintext, plaintextLen, &output);
...
Example 1
may run successfully, but anyone who has access to it will be able to figure out that it uses an empty HMAC key. After the program ships, there is likely no way to change the empty HMAC key unless the program is patched. A devious employee with access to this information could use it to compromise the HMAC function. Also, the code in Example 1
is vulnerable to forgery and key recovery attacks.
import hmac
...
mac = hmac.new("", plaintext).hexdigest()
...
Example 1
may run successfully, but anyone who has access to it will be able to figure out that it uses an empty HMAC key. After the program ships, there is likely no way to change the empty HMAC key unless the program is patched. A devious employee with access to this information could use it to compromise the HMAC function. Also, the code in Example 1
is vulnerable to forgery and key recovery attacks.
...
digest = OpenSSL::HMAC.digest('sha256', '', data)
...
Example 1
may run successfully, but anyone who has access to it will be able to figure out that it uses an empty HMAC key. After the program ships, there is likely no way to change the empty HMAC key unless the program is patched. A devious employee with access to this information could use it to compromise the HMAC function. Also, the code in Example 1
is vulnerable to forgery and key recovery attacks.
...
CCHmac(UInt32(kCCHmacAlgSHA256), "", 0, plaintext, plaintextLen, &output)
...
Example 1
may run successfully, but anyone who has access to it will be able to figure out that it uses an empty HMAC key. After the program ships, there is likely no way to change the empty HMAC key unless the program is patched. A devious employee with access to this information could use it to compromise the HMAC function. Also, the code in Example 1
is vulnerable to forgery and key recovery attacks.
...
Rfc2898DeriveBytes rdb = new Rfc2898DeriveBytes("", salt,100000);
...
...
var encryptor = new StrongPasswordEncryptor();
var encryptedPassword = encryptor.encryptPassword("");
...
const pbkdfPassword = "";
crypto.pbkdf2(
pbkdfPassword,
salt,
numIterations,
keyLen,
hashAlg,
function (err, derivedKey) { ... }
)
...
CCKeyDerivationPBKDF(kCCPBKDF2,
"",
0,
salt,
saltLen
kCCPRFHmacAlgSHA256,
100000,
derivedKey,
derivedKeyLen);
...
...
CCKeyDerivationPBKDF(kCCPBKDF2,
password,
0,
salt,
saltLen
kCCPRFHmacAlgSHA256,
100000,
derivedKey,
derivedKeyLen);
...
password
contains a strong, appropriately managed password value, passing its length as zero will result in an empty, null
, or otherwise unexpected weak password value.
...
$zip = new ZipArchive();
$zip->open("test.zip", ZipArchive::CREATE);
$zip->setEncryptionIndex(0, ZipArchive::EM_AES_256, "");
...
from hashlib import pbkdf2_hmac
...
dk = pbkdf2_hmac('sha256', '', salt, 100000)
...
...
key = OpenSSL::PKCS5::pbkdf2_hmac('', salt, 100000, 256, 'SHA256')
...
...
CCKeyDerivationPBKDF(CCPBKDFAlgorithm(kCCPBKDF2),
"",
0,
salt,
saltLen,
CCPseudoRandomAlgorithm(kCCPRFHmacAlgSHA256),
100000,
derivedKey,
derivedKeyLen)
...
...
CCKeyDerivationPBKDF(CCPBKDFAlgorithm(kCCPBKDF2),
password,
0,
salt,
saltLen,
CCPseudoRandomAlgorithm(kCCPRFHmacAlgSHA256),
100000,
derivedKey,
derivedKeyLen)
...
password
contains a strong, appropriately managed password value, passing its length as zero will result in an empty, null
, or otherwise unexpected weak password value.
...
encryptionKey = "lakdsljkalkjlksdfkl".
...
...
var encryptionKey:String = "lakdsljkalkjlksdfkl";
var key:ByteArray = Hex.toArray(Hex.fromString(encryptionKey));
...
var aes.ICipher = Crypto.getCipher("aes-cbc", key, padding);
...
...
Blob encKey = Blob.valueOf('YELLOW_SUBMARINE');
Blob encrypted = Crypto.encrypt('AES128', encKey, iv, input);
...
...
using (SymmetricAlgorithm algorithm = SymmetricAlgorithm.Create("AES"))
{
string encryptionKey = "lakdsljkalkjlksdfkl";
byte[] keyBytes = Encoding.ASCII.GetBytes(encryptionKey);
algorithm.Key = keyBytes;
...
}
...
char encryptionKey[] = "lakdsljkalkjlksdfkl";
...
...
<cfset encryptionKey = "lakdsljkalkjlksdfkl" />
<cfset encryptedMsg = encrypt(msg, encryptionKey, 'AES', 'Hex') />
...
...
key := []byte("lakdsljkalkjlksd");
block, err := aes.NewCipher(key)
...
...
private static final String encryptionKey = "lakdsljkalkjlksdfkl";
byte[] keyBytes = encryptionKey.getBytes();
SecretKeySpec key = new SecretKeySpec(keyBytes, "AES");
Cipher encryptCipher = Cipher.getInstance("AES");
encryptCipher.init(Cipher.ENCRYPT_MODE, key);
...
...
var crypto = require('crypto');
var encryptionKey = "lakdsljkalkjlksdfkl";
var algorithm = 'aes-256-ctr';
var cipher = crypto.createCipher(algorithm, encryptionKey);
...
...
{
"username":"scott"
"password":"tiger"
}
...
...
NSString encryptionKey = "lakdsljkalkjlksdfkl";
...
...
$encryption_key = 'hardcoded_encryption_key';
//$filter = new Zend_Filter_Encrypt('hardcoded_encryption_key');
$filter = new Zend_Filter_Encrypt($encryption_key);
$filter->setVector('myIV');
$encrypted = $filter->filter('text_to_be_encrypted');
print $encrypted;
...
...
from Crypto.Ciphers import AES
encryption_key = b'_hardcoded__key_'
cipher = AES.new(encryption_key, AES.MODE_CFB, iv)
msg = iv + cipher.encrypt(b'Attack at dawn')
...
_hardcoded__key_
unless the program is patched. A devious employee with access to this information can use it to compromise data encrypted by the system.
require 'openssl'
...
encryption_key = 'hardcoded_encryption_key'
...
cipher = OpenSSL::Cipher::AES.new(256, 'GCM')
cipher.encrypt
...
cipher.key=encryption_key
...
Example 2: The following code performs AES encryption using a hardcoded encryption key:
...
let encryptionKey = "YELLOW_SUBMARINE"
...
...
CCCrypt(UInt32(kCCEncrypt),
UInt32(kCCAlgorithmAES128),
UInt32(kCCOptionPKCS7Padding),
"YELLOW_SUBMARINE",
16,
iv,
plaintext,
plaintext.length,
ciphertext.mutableBytes,
ciphertext.length,
&numBytesEncrypted)
...
...
-----BEGIN RSA PRIVATE KEY-----
MIICXwIBAAKBgQCtVacMo+w+TFOm0p8MlBWvwXtVRpF28V+o0RNPx5x/1TJTlKEl
...
DiJPJY2LNBQ7jS685mb6650JdvH8uQl6oeJ/aUmq63o2zOw=
-----END RSA PRIVATE KEY-----
...
...
Dim encryptionKey As String
Set encryptionKey = "lakdsljkalkjlksdfkl"
Dim AES As New System.Security.Cryptography.RijndaelManaged
On Error GoTo ErrorHandler
AES.Key = System.Text.Encoding.ASCII.GetBytes(encryptionKey)
...
Exit Sub
...
...
production:
secret_key_base: 0ab25e26286c4fb9f7335947994d83f19861354f19702b7bbb84e85310b287ba3cdc348f1f19c8cdc08a7c6c5ad2c20ad31ecda177d2c74aa2d48ec4a346c40e
...
...
DATA: lo_hmac TYPE Ref To cl_abap_hmac,
Input_string type string.
CALL METHOD cl_abap_hmac=>get_instance
EXPORTING
if_algorithm = 'SHA3'
if_key = 'secret_key'
RECEIVING
ro_object = lo_hmac.
" update HMAC with input
lo_hmac->update( if_data = input_string ).
" finalise hmac
lo_digest->final( ).
...
...
using (HMAC hmac = HMAC.Create("HMACSHA512"))
{
string hmacKey = "lakdsljkalkjlksdfkl";
byte[] keyBytes = Encoding.ASCII.GetBytes(hmacKey);
hmac.Key = keyBytes;
...
}
import "crypto/hmac"
...
hmac.New(sha256.New, []byte("secret"))
...
...
private static String hmacKey = "lakdsljkalkjlksdfkl";
byte[] keyBytes = hmacKey.getBytes();
...
SecretKeySpec key = new SecretKeySpec(keyBytes, "SHA1");
Mac hmac = Mac.getInstance("HmacSHA1");
hmac.init(key);
...
const hmacKey = "a secret";
const hmac = createHmac('sha256', hmacKey);
hmac.update(data);
...
hmacKey
unless the program is patched. A devious employee with access to this information could use it to compromise the HMAC function.
...
CCHmac(kCCHmacAlgSHA256, "secret", 6, plaintext, plaintextLen, &output);
...
import hmac
...
mac = hmac.new("secret", plaintext).hexdigest()
...
...
digest = OpenSSL::HMAC.digest('sha256', 'secret_key', data)
...
...
CCHmac(UInt32(kCCHmacAlgSHA256), "secret", 6, plaintext, plaintextLen, &output)
...
...
Rfc2898DeriveBytes rdb = new Rfc2898DeriveBytes("password", salt,100000);
...
...
var encryptor = new StrongPasswordEncryptor();
var encryptedPassword = encryptor.encryptPassword("password");
...
const pbkdfPassword = "a secret";
crypto.pbkdf2(
pbkdfPassword,
salt,
numIterations,
keyLen,
hashAlg,
function (err, derivedKey) { ... }
)
...
CCKeyDerivationPBKDF(kCCPBKDF2,
"secret",
6,
salt,
saltLen
kCCPRFHmacAlgSHA256,
100000,
derivedKey,
derivedKeyLen);
...
...
$zip = new ZipArchive();
$zip->open("test.zip", ZipArchive::CREATE);
$zip->setEncryptionIndex(0, ZipArchive::EM_AES_256, "hardcodedpassword");
...
from hashlib import pbkdf2_hmac
...
dk = pbkdf2_hmac('sha256', 'password', salt, 100000)
...
...
key = OpenSSL::PKCS5::pbkdf2_hmac('password', salt, 100000, 256, 'SHA256')
...
...
CCKeyDerivationPBKDF(CCPBKDFAlgorithm(kCCPBKDF2),
"secret",
6,
salt,
saltLen,
CCPseudoRandomAlgorithm(kCCPRFHmacAlgSHA256),
100000,
derivedKey,
derivedKeyLen)
...
Null
encryption keys can compromise security in a way that is not easy to remedy.null
encryption key because it significantly reduces the protection afforded by a good encryption algorithm, but it also makes fixing the problem extremely difficult. After the offending code is in production, a software patch is required to change the null
encryption key. If an account that is protected by the null
encryption key is compromised, the owners of the system must choose between security and availability.null
encryption key:
...
var encryptionKey:ByteArray = null;
...
var aes.ICipher = Crypto.getCipher("aes-cbc", encryptionKey, padding);
...
null
encryption key, but anyone with even basic cracking techniques is much more likely to successfully decrypt any encrypted data. After the application has shipped, a software patch is required to change the null
encryption key. An employee with access to this information can use it to break into the system. Even if attackers only had access to the application's executable, they could extract evidence of the use of a null
encryption key.Null
encryption keys can compromise security in a way that is not easy to remedy.null
encryption key. Not only does using a null
encryption key significantly reduce the protection afforded by a good encryption algorithm, but it also makes fixing the problem extremely difficult. After the offending code is in production, a software patch is required to change the null
encryption key. If an account protected by the null
encryption key is compromised, the owners of the system must choose between security and availability.null
encryption key:
...
char encryptionKey[] = null;
...
null
encryption key, but anyone with even basic cracking techniques is much more likely to successfully decrypt any encrypted data. After the program ships, a software patch is required to change the null
encryption key. An employee with access to this information can use it to break into the system. Even if attackers only had access to the application's executable, they could extract evidence of the use of a null
encryption key.null
encryption key because it significantly reduces the protection afforded by a good encryption algorithm, and it is extremely difficult to fix the problem. After the offending code is in production, changing the null
encryption key requires a software patch. If an account that is protected by the null
encryption key is compromised, the owners of the system must choose between security and availability.null
encryption key:
...
aes.NewCipher(nil)
...
null
encryption key. Additionally, anyone with even basic cracking techniques is much more likely to successfully decrypt any encrypted data. After the application has shipped, a software patch is required to change the null
encryption key. An employee with access to this information can use it to break into the system. Even if attackers only had access to the application's executable, they could extract evidence of the use of a null
encryption key.null
encryption key because it significantly reduces the protection afforded by a good encryption algorithm, but it also makes fixing the problem extremely difficult. After the offending code is in production, a software patch is required to change the null
encryption key. If an account that is protected by the null
encryption key is compromised, the owners of the system must choose between security and availability.null
encryption key:
...
SecretKeySpec key = null;
....
Cipher encryptCipher = Cipher.getInstance("AES");
encryptCipher.init(Cipher.ENCRYPT_MODE, key);
...
null
encryption key, but anyone with even basic cracking techniques is much more likely to successfully decrypt any encrypted data. After the application has shipped, a software patch is required to change the null
encryption key. An employee with access to this information can use it to break into the system. Even if attackers only had access to the application's executable, they could extract evidence of the use of a null
encryption key.null
encryption key because it significantly reduces the protection afforded by a good encryption algorithm, but it also makes fixing the problem extremely difficult. After the offending code is in production, a software patch is required to change the null
encryption key. If an account that is protected by the null
encryption key is compromised, the owners of the system must choose between security and availability.null
encryption key:
...
var crypto = require('crypto');
var encryptionKey = null;
var algorithm = 'aes-256-ctr';
var cipher = crypto.createCipher(algorithm, encryptionKey);
...
null
encryption key, but anyone with even basic cracking techniques is much more likely to successfully decrypt any encrypted data. After the application has shipped, a software patch is required to change the null
encryption key. An employee with access to this information can use it to break into the system. Even if attackers only had access to the application's executable, they could extract evidence of the use of a null
encryption key.null
encryption key because it significantly reduces the protection afforded by a good encryption algorithm, but it also makes fixing the problem extremely difficult. After the offending code is in production, a software patch is required to change the null
encryption key. If an account that is protected by the null
encryption key is compromised, the owners of the system must choose between security and availability.null
encryption key:
...
CCCrypt(kCCEncrypt,
kCCAlgorithmAES,
kCCOptionPKCS7Padding,
nil,
0,
iv,
plaintext,
sizeof(plaintext),
ciphertext,
sizeof(ciphertext),
&numBytesEncrypted);
...
null
encryption key, but anyone with even basic cracking techniques is much more likely to successfully decrypt any encrypted data. After the application has shipped, a software patch is required to change the null
encryption key. An employee with access to this information can use it to break into the system. Even if attackers only had access to the application's executable, they could extract evidence of the use of a null
encryption key.null
to encryption key variables is a bad idea because it can allow attackers to expose sensitive and encrypted information. Not only does using a null
encryption key significantly reduce the protection afforded by a good encryption algorithm, but it also makes fixing the problem extremely difficult. After the offending code is in production, a software patch is required to change the null
encryption key. If an account protected by the null
encryption key is compromised, the owners of the system must choose between security and availability.null
.
...
$encryption_key = NULL;
$filter = new Zend_Filter_Encrypt($encryption_key);
$filter->setVector('myIV');
$encrypted = $filter->filter('text_to_be_encrypted');
print $encrypted;
...
null
encryption key, and anyone employing even basic cracking techniques is much more likely to successfully decrypt any encrypted data. After the program ships, a software patch is required to change the null
encryption key. An employee with access to this information can use it to break into the system. Even if attackers only had access to the application's executable, they could extract evidence of the use of a null
encryption key.null
encryption key because it significantly reduces the protection afforded by a good encryption algorithm, but it also makes fixing the problem extremely difficult. After the offending code is in production, a software patch is required to change the null
encryption key. If an account that is protected by the null
encryption key is compromised, the owners of the system must choose between security and availability.null
encryption key, but anyone with even basic cracking techniques is much more likely to successfully decrypt any encrypted data. After the application has shipped, a software patch is required to change the null
encryption key. An employee with access to this information can use it to break into the system. Even if attackers only had access to the application's executable, they could extract evidence of the use of a null
encryption key.None
to encryption key variables is a bad idea because it can allow attackers to expose sensitive and encrypted information. Not only does using a null
encryption key significantly reduce the protection afforded by a good encryption algorithm, but it also makes fixing the problem extremely difficult. After the offending code is in production, a software patch is required to change the null
encryption key. If an account protected by the null
encryption key is compromised, the owners of the system must choose between security and availability.null
.
...
from Crypto.Ciphers import AES
cipher = AES.new(None, AES.MODE_CFB, iv)
msg = iv + cipher.encrypt(b'Attack at dawn')
...
null
encryption key, and anyone employing even basic cracking techniques is much more likely to successfully decrypt any encrypted data. After the program ships, a software patch is required to change the null
encryption key. An employee with access to this information can use it to break into the system. Even if attackers only had access to the application's executable, they could extract evidence of the use of a null
encryption key.null
encryption key. Not only does using a null
encryption key significantly reduce the protection afforded by a good encryption algorithm, but it also makes fixing the problem extremely difficult. After the offending code is in production, a software patch is required to change the null
encryption key. If an account protected by the null
encryption key is compromised, the owners of the system must choose between security and availability.null
encryption key, and anyone employing even basic cracking techniques is much more likely to successfully decrypt any encrypted data. After the program ships, a software patch is required to change the null
encryption key. An employee with access to this information can use it to break into the system. Even if attackers only had access to the application's executable, they could extract evidence of the use of a null
encryption key.Null
encryption keys can compromise security in a way that is not easy to remedy.null
encryption key. Not only does using a null
encryption key significantly reduce the protection afforded by a good encryption algorithm, but it also makes fixing the problem extremely difficult. After the offending code is in production, a software patch is required to change the null
encryption key. If an account protected by the null
encryption key is compromised, the owners of the system must choose between security and availability.null
encryption key:
...
CCCrypt(UInt32(kCCEncrypt),
UInt32(kCCAlgorithmAES128),
UInt32(kCCOptionPKCS7Padding),
nil,
0,
iv,
plaintext,
plaintext.length,
ciphertext.mutableBytes,
ciphertext.length,
&numBytesEncrypted)
...
null
encryption key, but anyone with even basic cracking techniques is much more likely to successfully decrypt any encrypted data. After the program ships, a software patch is required to change the null
encryption key. An employee with access to this information can use it to break into the system. Even if attackers only had access to the application's executable, they could extract evidence of the use of a null
encryption key.null
encryption key because it significantly reduces the protection afforded by a good encryption algorithm, but it also makes fixing the problem extremely difficult. After the offending code is in production, a software patch is required to change the null
encryption key. If an account that is protected by the null
encryption key is compromised, the owners of the system must choose between security and availability.null
encryption key:
...
Dim encryptionKey As String
Set encryptionKey = vbNullString
Dim AES As New System.Security.Cryptography.RijndaelManaged
On Error GoTo ErrorHandler
AES.Key = System.Text.Encoding.ASCII.GetBytes(encryptionKey)
...
Exit Sub
...
null
encryption key, but anyone with even basic cracking techniques is much more likely to successfully decrypt any encrypted data. After the application has shipped, a software patch is required to change the null
encryption key. An employee with access to this information can use it to break into the system. Even if attackers only had access to the application's executable, they could extract evidence of the use of a null
encryption key.null
password may compromise system security in a way that is not easy to remedy.null
value as the password argument to a cryptographic password-based key derivation function. In this scenario, the resulting derived key will be based solely on the provided salt (rendering it significantly weaker), and fixing the problem is extremely difficult. After the offending code is in production, the null
password often cannot be changed without patching the software. If an account protected by a derived key based on a null
password is compromised, the owners of the system might be forced to choose between security and availability.null
value as the password argument to a cryptographic password-based key derivation function:
...
var encryptor = new StrongPasswordEncryptor();
var encryptedPassword = encryptor.encryptPassword(null);
...
null
password argument, but anyone with even basic cracking techniques is much more likely to successfully gain access to any resources protected by the offending keys. If an attacker also has access to the salt value used to generate any of the keys based on a null
password, cracking those keys becomes trivial. After the program ships, there is likely no way to change the null
password unless the program is patched. An employee with access to this information can use it to break into the system. Even if attackers only had access to the application's executable, they could extract evidence of the use of a null
password.null
password may compromise system security in a way that is not easy to remedy.null
value as the password argument to a cryptographic password-based key derivation function. In this scenario, the resulting derived key will be based solely on the provided salt (rendering it significantly weaker), and fixing the problem is extremely difficult. After the offending code is in production, the null
password often cannot be changed without patching the software. If an account protected by a derived key based on a null
password is compromised, the owners of the system might be forced to choose between security and availability.null
value as the password argument to a cryptographic password-based key derivation function:
...
CCKeyDerivationPBKDF(kCCPBKDF2,
nil,
0,
salt,
saltLen
kCCPRFHmacAlgSHA256,
100000,
derivedKey,
derivedKeyLen);
...
null
password argument, but anyone with even basic cracking techniques is much more likely to successfully gain access to any resources protected by the offending keys. If an attacker also has access to the salt value used to generate any of the keys based on a null
password, cracking those keys becomes trivial. After the program ships, there is likely no way to change the null
password unless the program is patched. An employee with access to this information can use it to break into the system. Even if attackers only had access to the application's executable, they could extract evidence of the use of a null
password.null
password may compromise system security in a way that is not easy to remedy.null
value as the password argument to a cryptographic password-based key derivation function. In this scenario, the resulting derived key will be based solely on the provided salt (rendering it significantly weaker), and fixing the problem is extremely difficult. After the offending code is in production, the null
password often cannot be changed without patching the software. If an account protected by a derived key based on a null
password is compromised, the owners of the system might be forced to choose between security and availability.null
value as the password argument to a cryptographic password-based key derivation function:
...
CCKeyDerivationPBKDF(CCPBKDFAlgorithm(kCCPBKDF2),
nil,
0,
salt,
saltLen,
CCPseudoRandomAlgorithm(kCCPRFHmacAlgSHA256),
100000,
derivedKey,
derivedKeyLen)
...
null
password argument, but anyone with even basic cracking techniques is much more likely to successfully gain access to any resources protected by the offending keys. If an attacker also has access to the salt value used to generate any of the keys based on a null
password, cracking those keys becomes trivial. After the program ships, there is likely no way to change the null
password unless the program is patched. An employee with access to this information can use it to break into the system. Even if attackers only had access to the application's executable, they could extract evidence of the use of a null
password.
from Crypto.PublicKey import RSA
key = RSA.generate(2048)
f = open('mykey.pem','w')
f.write(key.exportKey(format='PEM'))
f.close()
require 'openssl'
key = OpenSSL::PKey::RSA.new 2048
File.open('mykey.pem', 'w') do |file|
file.write(key.to_pem)
end
returningObjectFlag
to true
on the javax.naming.directory.SearchControls
instance passed to the search
method or by using a library function that sets this flag on its behalf.
<beans ... >
<authentication-manager>
<ldap-authentication-provider
user-search-filter="(uid={0})"
user-search-base="ou=users,dc=example,dc=org"
group-search-filter="(uniqueMember={0})"
group-search-base="ou=groups,dc=example,dc=org"
group-role-attribute="cn"
role-prefix="ROLE_">
</ldap-authentication-provider>
</authentication-manager>
</beans>
chroot()
should be dropped immediately after the operation is performed.chroot()
, it must first acquire root
privilege. As soon as the privileged operation has completed, the program should drop root
privilege and return to the privilege level of the invoking user.chroot()
to restrict the application to a subset of the file system below APP_HOME
in order to prevent an attacker from using the program to gain unauthorized access to files located elsewhere. The code then opens a file specified by the user and processes the contents of the file.
...
chroot(APP_HOME);
chdir("/");
FILE* data = fopen(argv[1], "r+");
...
setuid()
with some non-zero value means the application is continuing to operate with unnecessary root
privileges. Any successful exploit carried out by an attacker against the application can now result in a privilege escalation attack because any malicious operations will be performed with the privileges of the superuser. If the application drops to the privilege level of a non-root
user, the potential for damage is substantially reduced.
...
DATA log_msg TYPE bal_s_msg.
val = request->get_form_field( 'val' ).
log_msg-msgid = 'XY'.
log_msg-msgty = 'E'.
log_msg-msgno = '123'.
log_msg-msgv1 = 'VAL: '.
log_msg-msgv2 = val.
CALL FUNCTION 'BAL_LOG_MSG_ADD'
EXPORTING
I_S_MSG = log_msg
EXCEPTIONS
LOG_NOT_FOUND = 1
MSG_INCONSISTENT = 2
LOG_IS_FULL = 3
OTHERS = 4.
...
FOO
" for val
, the following entry is logged:
XY E 123 VAL: FOO
FOO XY E 124 VAL: BAR
", the following entry is logged:
XY E 123 VAL: FOO XY E 124 VAL: BAR
var params:Object = LoaderInfo(this.root.loaderInfo).parameters;
var val:String = String(params["username"]);
var value:Number = parseInt(val);
if (value == Number.NaN) {
trace("Failed to parse val = " + val);
}
twenty-one
" for val
, the following entry is logged:
Failed to parse val=twenty-one
twenty-one%0a%0aINFO:+User+logged+out%3dbadguy
", the following entry is logged:
Failed to parse val=twenty-one
User logged out=badguy
...
string val = (string)Session["val"];
try {
int value = Int32.Parse(val);
}
catch (FormatException fe) {
log.Info("Failed to parse val= " + val);
}
...
twenty-one
" for val
, the following entry is logged:
INFO: Failed to parse val=twenty-one
twenty-one%0a%0aINFO:+User+logged+out%3dbadguy
", the following entry is logged:
INFO: Failed to parse val=twenty-one
INFO: User logged out=badguy
long value = strtol(val, &endPtr, 10);
if (*endPtr != '\0')
syslog(LOG_INFO,"Illegal value = %s",val);
...
twenty-one
" for val
, the following entry is logged:
Illegal value=twenty-one
twenty-one\n\nINFO: User logged out=evil
", the following entry is logged:
INFO: Illegal value=twenty-one
INFO: User logged out=evil
...
01 LOGAREA.
05 VALHEADER PIC X(50) VALUE 'VAL: '.
05 VAL PIC X(50).
...
EXEC CICS
WEB READ
FORMFIELD(NAME)
VALUE(VAL)
...
END-EXEC.
EXEC DLI
LOG
FROM(LOGAREA)
LENGTH(50)
END-EXEC.
...
FOO
" for VAL
, the following entry is logged:
VAL: FOO
FOO VAL: BAR
", the following entry is logged:
VAL: FOO VAL: BAR
<cflog file="app_log" application="No" Thread="No"
text="Failed to parse val="#Form.val#">
twenty-one
" for val
, the following entry is logged:
"Information",,"02/28/01","14:50:37",,"Failed to parse val=twenty-one"
twenty-one%0a%0a%22Information%22%2C%2C%2202/28/01%22%2C%2214:53:40%22%2C%2C%22User%20logged%20out:%20badguy%22
", the following entry is logged:
"Information",,"02/28/01","14:50:37",,"Failed to parse val=twenty-one"
"Information",,"02/28/01","14:53:40",,"User logged out: badguy"
func someHandler(w http.ResponseWriter, r *http.Request){
r.parseForm()
name := r.FormValue("name")
logout := r.FormValue("logout")
...
if (logout){
...
} else {
log.Printf("Attempt to log out: name: %s logout: %s", name, logout)
}
}
twenty-one
" for logout
and he was able to create a user with name "admin
", the following entry is logged:
Attempt to log out: name: admin logout: twenty-one
admin+logout:+1+++++++++++++++++++++++
", the following entry is logged:
Attempt to log out: name: admin logout: 1 logout: twenty-one
...
String val = request.getParameter("val");
try {
int value = Integer.parseInt(val);
}
catch (NumberFormatException nfe) {
log.info("Failed to parse val = " + val);
}
...
twenty-one
" for val
, the following entry is logged:
INFO: Failed to parse val=twenty-one
twenty-one%0a%0aINFO:+User+logged+out%3dbadguy
", the following entry is logged:
INFO: Failed to parse val=twenty-one
INFO: User logged out=badguy
Example 1
to the Android platform.
...
String val = this.getIntent().getExtras().getString("val");
try {
int value = Integer.parseInt();
}
catch (NumberFormatException nfe) {
Log.e(TAG, "Failed to parse val = " + val);
}
...
var cp = require('child_process');
var http = require('http');
var url = require('url');
function listener(request, response){
var val = url.parse(request.url, true)['query']['val'];
if (isNaN(val)){
console.log("INFO: Failed to parse val = " + val);
}
...
}
...
http.createServer(listener).listen(8080);
...
twenty-one
" for val
, the following entry is logged:
INFO: Failed to parse val = twenty-one
twenty-one%0a%0aINFO:+User+logged+out%3dbadguy
", the following entry is logged:
INFO: Failed to parse val=twenty-one
INFO: User logged out=badguy
long value = strtol(val, &endPtr, 10);
if (*endPtr != '\0')
NSLog("Illegal value = %s",val);
...
twenty-one
" for val
, the following entry is logged:
INFO: Illegal value=twenty-one
twenty-one\n\nINFO: User logged out=evil
", the following entry is logged:
INFO: Illegal value=twenty-one
INFO: User logged out=evil
<?php
$name =$_GET['name'];
...
$logout =$_GET['logout'];
if(is_numeric($logout))
{
...
}
else
{
trigger_error("Attempt to log out: name: $name logout: $val");
}
?>
twenty-one
" for logout
and he was able to create a user with name "admin
", the following entry is logged:
PHP Notice: Attempt to log out: name: admin logout: twenty-one
admin+logout:+1+++++++++++++++++++++++
", the following entry is logged:
PHP Notice: Attempt to log out: name: admin logout: 1 logout: twenty-one
name = req.field('name')
...
logout = req.field('logout')
if (logout):
...
else:
logger.error("Attempt to log out: name: %s logout: %s" % (name,logout))
twenty-one
" for logout
and he was able to create a user with name "admin
", the following entry is logged:
Attempt to log out: name: admin logout: twenty-one
admin+logout:+1+++++++++++++++++++++++
", the following entry is logged:
Attempt to log out: name: admin logout: 1 logout: twenty-one
...
val = req['val']
unless val.respond_to?(:to_int)
logger.info("Failed to parse val")
logger.info(val)
end
...
twenty-one
" for val
, the following entry is logged:
INFO: Failed to parse val
INFO: twenty-one
twenty-one%0a%0aINFO:+User+logged+out%3dbadguy
", the following entry is logged:
INFO: Failed to parse val
INFO: twenty-one
INFO: User logged out=badguy
...
let num = Int(param)
if num == nil {
NSLog("Illegal value = %@", param)
}
...
twenty-one
" for val
, the following entry is logged:
INFO: Illegal value = twenty-one
twenty-one\n\nINFO: User logged out=evil
", the following entry is logged:
INFO: Illegal value=twenty-one
INFO: User logged out=evil
...
Dim Val As Variant
Dim Value As Integer
Set Val = Request.Form("val")
If IsNumeric(Val) Then
Set Value = Val
Else
App.EventLog "Failed to parse val=" & Val, 1
End If
...
twenty-one
" for val
, the following entry is logged:
Failed to parse val=twenty-one
twenty-one%0a%0a+User+logged+out%3dbadguy
", the following entry is logged:
Failed to parse val=twenty-one
User logged out=badguy