輸入驗證和表示法問題是由中繼字元、替代編碼和數值表示法引起的。信任輸入會導致安全問題。問題包括:「Buffer Overflows」、「Cross-Site Scripting」攻擊、「SQL Injection」及其他許多問題。
select()
查詢,以搜尋符合使用者指定產品類別的清單。使用者還可以指定欄按結果排序。假設應用程式已經過適當驗證,並已在此程式碼片段之前設定 customerID
的值。
...
String customerID = getAuthenticatedCustomerID(customerName, customerCredentials);
...
AmazonSimpleDBClient sdbc = new AmazonSimpleDBClient(appAWSCredentials);
String query = "select * from invoices where productCategory = '"
+ productCategory + "' and customerID = '"
+ customerID + "' order by '"
+ sortColumn + "' asc";
SelectResult sdbResult = sdbc.select(new SelectRequest(query));
...
select * from invoices
where productCategory = 'Fax Machines'
and customerID = '12345678'
order by 'price' asc
productCategory
和 price
不包含單引號字元的時候,查詢才會正確執行。但是,如果攻擊者提供「Fax Machines' or productCategory = \"
」字串給 productCategory
和「\" order by 'price
」字串給 sortColumn
,那麼查詢將會變為:
select * from invoices
where productCategory = 'Fax Machines' or productCategory = "'
and customerID = '12345678'
order by '" order by 'price' asc
select * from invoices
where productCategory = 'Fax Machines'
or productCategory = "' and customerID = '12345678' order by '"
order by 'price' asc
customerID
所需的 Authentication,並允許攻擊者檢視所有符合 'Fax Machines'
清單記錄的客戶。customerID
的值。
...
productCategory = this.getIntent().getExtras().getString("productCategory");
sortColumn = this.getIntent().getExtras().getString("sortColumn");
customerID = getAuthenticatedCustomerID(customerName, customerCredentials);
c = invoicesDB.query(Uri.parse(invoices), columns, "productCategory = '" + productCategory + "' and customerID = '" + customerID + "'", null, null, null, "'" + sortColumn + "'asc", null);
...
select * from invoices
where productCategory = 'Fax Machines'
and customerID = '12345678'
order by 'price' asc
productCategory
所動態建構而成,所以只有在 productCategory
和 sortColumn
不包含單引號字元時,查詢才會正確執行。如果攻擊者提供「Fax Machines' or productCategory = \"
」字串給 productCategory
和「\" order by 'price
」字串給 sortColumn
,那麼查詢將會變為:
select * from invoices
where productCategory = 'Fax Machines' or productCategory = "'
and customerID = '12345678'
order by '" order by 'price' asc
select * from invoices
where productCategory = 'Fax Machines'
or productCategory = "' and customerID = '12345678' order by '"
order by 'price' asc
customerID
所需的 Authentication,並允許攻擊者檢視所有符合 'Fax Machines'
清單記錄的客戶。Content-Disposition
表頭設定錯誤,從而讓攻擊者可控制 HTTP 回應中的 Content-Type
和/或 Content-Disposition
表頭,或者目標應用程式所包含的 Content-Type
預設並非在瀏覽器中轉譯。ContentNegotiationManager
來動態產生不同的回應格式,則滿足使 RFD 攻擊成為可能所需的條件。ContentNegotiationManager
設定為根據要求路徑副檔名來決定回應格式,並使用 Java Activation Framework (JAF) 尋找更為符合用戶端所要求之格式的 Content-Type
。它還允許用戶端透過在要求的 Accept
表頭中傳送的媒體類型來指定回應內容類型。範例 2:在以下範例中,應用程式設定為允許要求的
<bean id="contentNegotiationManager" class="org.springframework.web.accept.ContentNegotiationManagerFactoryBean">
<property name="favorPathExtension" value="true" />
<property name="useJaf" value="true" />
</bean>
Accept
表頭來決定回應的內容類型:
<bean id="contentNegotiationManager" class="org.springframework.web.accept.ContentNegotiationManagerFactoryBean">
<property name="ignoreAcceptHeader" value="false" />
</bean>
ContentNegotiationManagerFactoryBean
屬性預設值如下:useJaf
:true
favorPathExtension
:true
ignoreAcceptHeader
:false
Example 1
中所顯示的配置可讓攻擊者製作惡意 URL,如:ContentNegotiationManager
使用 Java Activation Framework (如果在類別路徑中找到 activation.jar) 嘗試解析指定副檔名的媒體類型,並相應設定回應的 ContentType
表頭。此範例中的副檔名為「.bat」,從而產生 application/x-msdownload
的 Content-Type
表頭 (儘管確切的 Content-Type
可能依據伺服器 OS 和 JAF 組態而有所不同)。因此,一旦受害者造訪此惡意 URL,他/她的機器便會自動開始下載包含攻擊者控制內容的「.bat」檔案。如果隨後執行此檔案,受害者機器便會執行攻擊者承載所指定的任意指令。
...
host_name = request->get_form_field( 'host' ).
CALL FUNCTION 'FTP_CONNECT'
EXPORTING
USER = user
PASSWORD = password
HOST = host_name
RFC_DESTINATION = 'SAPFTP'
IMPORTING
HANDLE = mi_handle
EXCEPTIONS
NOT_CONNECTED = 1
OTHERS = 2.
...
int rPort = Int32.Parse(Request.Item("rPort"));
...
IPEndPoint endpoint = new IPEndPoint(address,rPort);
socket = new Socket(endpoint.AddressFamily,
SocketType.Stream, ProtocolType.Tcp);
socket.Connect(endpoint);
...
...
char* rPort = getenv("rPort");
...
serv_addr.sin_port = htons(atoi(rPort));
if (connect(sockfd,&serv_addr,sizeof(serv_addr)) < 0)
error("ERROR connecting");
...
...
ACCEPT QNAME.
EXEC CICS
READQ TD
QUEUE(QNAME)
INTO(DATA)
LENGTH(LDATA)
END-EXEC.
...
ServerSocket
物件,並使用從 HTTP 要求讀取的連接埠號碼來建立通訊端。
<cfobject action="create" type="java" class="java.net.ServerSocket" name="myObj">
<cfset srvr = myObj.init(#url.port#)>
<cfset socket = srvr.accept()>
Passing user input to objects imported from other languages can be very dangerous.
final server = await HttpServer.bind('localhost', 18081);
server.listen((request) async {
final remotePort = headers.value('port');
final serverSocket = await ServerSocket.bind(host, remotePort as int);
final httpServer = HttpServer.listenOn(serverSocket);
});
...
func someHandler(w http.ResponseWriter, r *http.Request){
r.parseForm()
deviceName := r.FormValue("device")
...
syscall.BindToDevice(fd, deviceName)
}
String remotePort = request.getParameter("remotePort");
...
ServerSocket srvr = new ServerSocket(remotePort);
Socket skt = srvr.accept();
...
WebView
。
...
WebView webview = new WebView(this);
setContentView(webview);
String url = this.getIntent().getExtras().getString("url");
webview.loadUrl(url);
...
var socket = new WebSocket(document.URL.indexOf("url=")+20);
...
char* rHost = getenv("host");
...
CFReadStreamRef readStream;
CFWriteStreamRef writeStream;
CFStreamCreatePairWithSocketToHost(NULL, (CFStringRef)rHost, 80, &readStream, &writeStream);
...
<?php
$host=$_GET['host'];
$dbconn = pg_connect("host=$host port=1234 dbname=ticketdb");
...
$result = pg_prepare($dbconn, "my_query", 'SELECT * FROM pricelist WHERE name = $1');
$result = pg_execute($dbconn, "my_query", array("ticket"));
?>
...
filename := SUBSTR(OWA_UTIL.get_cgi_env('PATH_INFO'), 2);
WPG_DOCLOAD.download_file(filename);
...
host=request.GET['host']
dbconn = db.connect(host=host, port=1234, dbname=ticketdb)
c = dbconn.cursor()
...
result = c.execute('SELECT * FROM pricelist')
...
def controllerMethod = Action { request =>
val result = request.getQueryString("key").map { key =>
val user = db.getUser()
cache.set(key, user)
Ok("Cached Request")
}
Ok("Done")
}
...
func application(app: UIApplication, openURL url: NSURL, options: [String : AnyObject]) -> Bool {
var inputStream : NSInputStream?
var outputStream : NSOutputStream?
...
var readStream : Unmanaged<CFReadStream>?
var writeStream : Unmanaged<CFWriteStream>?
let rHost = getQueryStringParameter(url.absoluteString, "host")
CFStreamCreatePairWithSocketToHost(kCFAllocatorDefault, rHost, 80, &readStream, &writeStream);
...
}
func getQueryStringParameter(url: String?, param: String) -> String? {
if let url = url, urlComponents = NSURLComponents(string: url), queryItems = (urlComponents.queryItems as? [NSURLQueryItem]) {
return queryItems.filter({ (item) in item.name == param }).first?.value!
}
return nil
}
...
...
Begin MSWinsockLib.Winsock tcpServer
...
Dim Response As Response
Dim Request As Request
Dim Session As Session
Dim Application As Application
Dim Server As Server
Dim Port As Variant
Set Response = objContext("Response")
Set Request = objContext("Request")
Set Session = objContext("Session")
Set Application = objContext("Application")
Set Server = objContext("Server")
Set Port = Request.Form("port")
...
tcpServer.LocalPort = Port
tcpServer.Accept
...
@ControllerAdvice
public class JsonpAdvice extends AbstractJsonpResponseBodyAdvice {
public JsonpAdvice() {
super("callback");
}
}
GET /api/latest.json?callback=myCallbackFunction
的要求,控制項方法會產生一個諸如以下內容的回應:
HTTP/1.1 200 Ok
Content-Type: application/json; charset=utf-8
Date: Tue, 12 Dec 2017 16:16:04 GMT
Server: nginx/1.12.1
Content-Length: 225
Connection: Close
myCallbackFunction({<json>})
Script
標籤從 JSONP 端點載入回應,其會變成執行 myCallbackFunction
函數。 攻擊者可以使用不同的回呼名稱來導覽 DOM 並與之互動。 例如,opener.document.body.someElemnt.firstChild.nextElementSibling.submit
可用來在目標頁面中尋找表單並進行提交。
def myJSONPService(callback: String) = Action {
val json = getJSONToBeReturned()
Ok(Jsonp(callback, json))
}
GET /api/latest.json?callback=myCallbackFunction
的要求,Example 1
中所述的控制項方法會產生一個諸如以下內容的回應:
HTTP/1.1 200 Ok
Content-Type: application/json; charset=utf-8
Date: Tue, 12 Dec 2017 16:16:04 GMT
Server: nginx/1.12.1
Content-Length: 225
Connection: Close
myCallbackFunction({<json>})
Script
標籤從 JSONP 端點載入回應,其會變成執行 myCallbackFunction
函數。 攻擊者可以使用不同的回呼名稱來導覽 DOM 並與之互動。 例如,opener.document.body.someElemnt.firstChild.nextElementSibling.submit
可用來在目標頁面中尋找表單並進行提交。sanitizeValue
設定為 false
會允許未清理的輸入內容帶來 Cross-Site Scripting 等弱點。sanitizeValue
屬性決定在將值套用於 HTML 標記時是否執行 HTML 清理程式。輸入內容可能直接來自使用者,因此可以被認為是不安全的。出於多種原因,可以將 sanitizeValue
屬性設定為 false
,例如為了允許使用額外的輸入字元。但是,這樣做可能會無意中允許不安全的使用者輸入在程式碼中執行。將 sanitizeValue
屬性設定為 true
(也就是預設值) 比較安全。RichTextEditor
中的 sanitizeValue
屬性設定為 false
。
new RichTextEditor({
sanitizeValue: false,
value: input
}).placeAt("moreContent");
...
lv_uri = request->get_form_field( 'uri' ).
CALL METHOD cl_http_utility=>set_request_uri
EXPORTING
request = lo_request
uri = lv_uri.
...
http
或 https
的通訊協定,例如:
...
PageReference ref = ApexPages.currentPage();
Map<String,String> params = ref.getParameters();
HttpRequest req = new HttpRequest();
req.setEndpoint(params.get('url'));
HTTPResponse res = new Http().send(req);
http
或 https
的通訊協定,例如:
string url = Request.Form["url"];
HttpClient client = new HttpClient();
HttpResponseMessage response = await client.GetAsync(url);
http
或 https
的通訊協定,例如:
char *url = maliciousInput();
CURL *curl = curl_easy_init();
curl_easy_setopt(curl, CURLOPT_URL, url);
CURLcode res = curl_easy_perform(curl);
http
或 https
的通訊協定,例如:
...
final server = await HttpServer.bind('localhost', 18081);
server.listen((request) async {
final headers = request.headers;
final url = headers.value('url');
final client = IOClient();
final response = await client.get(Uri.parse(url!));
...
}
http
或 https
的通訊協定,例如:
url := request.Form.Get("url")
res, err =: http.Get(url)
...
http
或 https
的通訊協定,例如:
String url = request.getParameter("url");
CloseableHttpClient httpclient = HttpClients.createDefault();
HttpGet httpGet = new HttpGet(url);
CloseableHttpResponse response1 = httpclient.execute(httpGet);
http
或 https
的通訊協定,例如:
var http = require('http');
var url = require('url');
function listener(request, response){
var request_url = url.parse(request.url, true)['query']['url'];
http.request(request_url)
...
}
...
http.createServer(listener).listen(8080);
...
http
或 https
的通訊協定,例如:
val url: String = request.getParameter("url")
val httpclient: CloseableHttpClient = HttpClients.createDefault()
val httpGet = HttpGet(url)
val response1: CloseableHttpResponse = httpclient.execute(httpGet)
http
或 https
的通訊協定,例如:
$url = $_GET['url'];
$c = curl_init();
curl_setopt($c, CURLOPT_POST, 0);
curl_setopt($c,CURLOPT_URL,$url);
$response=curl_exec($c);
curl_close($c);
http
或 https
的通訊協定,例如:
url = request.GET['url']
handle = urllib.urlopen(url)
http
或 https
的通訊協定,例如:
url = req['url']
Net::HTTP.get(url)
http
或 https
的通訊協定,例如:
def getFile(url: String) = Action { request =>
...
val url = request.body.asText.getOrElse("http://google.com")
ws.url(url).get().map { response =>
Ok(s"Request sent to $url")
}
...
}
http
或 https
的通訊協定,例如:
// Set up the context data
VelocityContext context = new VelocityContext();
context.put( "name", user.name );
// Load the template
String template = getUserTemplateFromRequestBody(request);
RuntimeServices runtimeServices = RuntimeSingleton.getRuntimeServices();
StringReader reader = new StringReader(template);
SimpleNode node = runtimeServices.parse(reader, "myTemplate");
template = new Template();
template.setRuntimeServices(runtimeServices);
template.setData(node);
template.initDocument();
// Render the template with the context data
StringWriter sw = new StringWriter();
template.merge( context, sw );
Example 1
使用 Velocity
做為範本引擎。對於該引擎,攻擊者可提交下列範本以在伺服器上執行任意指令:
$name.getClass().forName("java.lang.Runtime").getRuntime().exec(<COMMAND>)
app.get('/', function(req, res){
var template = _.template(req.params['template']);
res.write("<html><body><h2>Hello World!</h2>" + template() + "</body></html>");
});
Example 1
使用 Underscore.js
做為 Node.js
應用程式內的範本引擎。對於該引擎,攻擊者可提交下列範本以在伺服器上執行任意指令:
<% cp = process.mainModule.require('child_process');cp.exec(<COMMAND>); %>
Jinja2
範本引擎轉譯範本。
from django.http import HttpResponse
from jinja2 import Template as Jinja2_Template
from jinja2 import Environment, DictLoader, escape
def process_request(request):
# Load the template
template = request.GET['template']
t = Jinja2_Template(template)
name = source(request.GET['name'])
# Render the template with the context data
html = t.render(name=escape(name))
return HttpResponse(html)
Example 1
使用 Jinja2
做為範本引擎。對於該引擎,攻擊者可提交下列範本以從伺服器讀取任意檔案:範例 2:以下範例顯示如何從 HTTP 要求擷取範本並使用
template={{''.__class__.__mro__[2].__subclasses__()[40]('/etc/passwd').read()}}
Django
範本引擎轉譯範本。
from django.http import HttpResponse
from django.template import Template, Context, Engine
def process_request(request):
# Load the template
template = source(request.GET['template'])
t = Template(template)
user = {"name": "John", "secret":getToken()}
ctx = Context(locals())
html = t.render(ctx)
return HttpResponse(html)
Example 2
使用 Django
做為範本引擎。對於該引擎,攻擊者將無法執行任意指令,但其能夠存取範本內容中的所有物件。在此範例中,已在內容中提供了秘密權杖,該權杖可能會被攻擊者洩漏。@SessionAttributes
註解的類別,意味著 Spring 複製了對階段作業物件中的模型屬性的變更。如果攻擊者能夠在模型屬性內儲存任意值,將會在可能受應用程式信任的階段作業物件中複製這些變更。如果階段作業屬性透過使用者無法修改的信任資料初始化,則攻擊者可以執行階段作業疑難攻擊並濫用應用程式邏輯。
@Controller
@SessionAttributes("user")
public class HomeController {
...
@RequestMapping(value= "/auth", method=RequestMethod.POST)
public String authHandler(@RequestParam String username, @RequestParam String password, RedirectAttributes attributes, Model model) {
User user = userService.findByNamePassword(username, password);
if (user == null) {
// Handle error
...
} else {
// Handle success
attributes.addFlashAttribute("user", user);
return "redirect:home";
}
}
...
}
@SessionAttributes("user")
註解,將嘗試從階段作業載入 User
實例,並使用它來驗證重設密碼問題。
@Controller
@SessionAttributes("user")
public class ResetPasswordController {
@RequestMapping(value = "/resetQuestion", method = RequestMethod.POST)
public String resetQuestionHandler(@RequestParam String answerReset, SessionStatus status, User user, Model model) {
if (!user.getAnswer().equals(answerReset)) {
// Handle error
...
} else {
// Handle success
...
}
}
}
user
實例從登入程序期間儲存所在的階段作業載入。但是,Spring 將會檢查要求並嘗試將其資料繫結至模型 user
實例。如果收到的要求包含可繫結至 User
類別的資料,Spring 會將收到的資料合併到使用者階段作業屬性。透過在 answerReset
查詢參數中提交任意答覆和相同的值覆寫階段作業中儲存的值,可濫用此案例。這樣一來,攻擊者可以為隨機使用者設定任意新密碼。
...
taintedConnectionStr = request->get_form_field( 'dbconn_name' ).
TRY.
DATA(con) = cl_sql_connection=>get_connection( `R/3*` && taintedConnectionStr ).
...
con->close( ).
CATCH cx_sql_exception INTO FINAL(exc).
...
ENDTRY.
...
sethostid(argv[1]);
...
sethostid()
,但是沒有被賦予權限的使用者也可能呼叫程式。這個範例中的程式碼允許使用者輸入直接控制系統設定的值。如果攻擊者向主機 ID 提供一個惡意值,攻擊者可能會誤認網路上受影響的機器,或者引發其他意料之外的行為。
...
ACCEPT OPT1.
ACCEPT OPT2
COMPUTE OPTS = OPT1 + OPT2.
CALL 'MQOPEN' USING HCONN, OBJECTDESC, OPTS, HOBJ, COMPOCODE REASON.
...
...
<cfset code = SetProfileString(IniPath,
Section, "timeout", Form.newTimeout)>
...
Form.newTimeout
的值用於定義逾時時間,所以攻擊者可以藉由定義超大的數值來啟動 denial of service (DoS),破壞應用程式的正常運作。
...
catalog := request.Form.Get("catalog")
path := request.Form.Get("path")
os.Setenv(catalog, path)
...
HttpServletRequest
讀取字串,並將該字串設定為資料庫 Connection
使用中的目錄。
...
conn.setCatalog(request.getParamter("catalog"));
...
http.IncomingMessage
要求變數中讀取字串,並使用它來設定額外的 V8 指令行旗標。
var v8 = require('v8');
...
var flags = url.parse(request.url, true)['query']['flags'];
...
v8.setFlagsFromString(flags);
...
<?php
...
$table_name=$_GET['catalog'];
$retrieved_array = pg_copy_to($db_connection, $table_name);
...
?>
...
catalog = request.GET['catalog']
path = request.GET['path']
os.putenv(catalog, path)
...
Connection
的使用中目錄。
def connect(catalog: String) = Action { request =>
...
conn.setCatalog(catalog)
...
}
...
sqlite3(SQLITE_CONFIG_LOG, user_controllable);
...
Request
物件讀取字串,並將該字串設定為資料庫 Connection
使用中的目錄。
...
Dim conn As ADODB.Connection
Set conn = New ADODB.Connection
Dim rsTables As ADODB.Recordset
Dim Catalog As New ADOX.Catalog
Set Catalog.ActiveConnection = conn
Catalog.Create Request.Form("catalog")
...
myModule.config(function($compileProvider){
$compileProvider.imgSrcSanitizationWhitelist(userInput);
});
/^(http(s)?|javascript):.*/
,則應用程式將允許在影像來源 URL 中使用內嵌 JavaScript,這可能會導致 Cross-site scripting 攻擊。ProcessWorkitemRequest.setAction()
呼叫中的核准動作。
void processRequest() {
String workItemId = ApexPages.currentPage().getParameters().get('Id');
String action = ApexPages.currentPage().getParameters().get('Action');
Approval.ProcessWorkitemRequest req = new Approval.ProcessWorkitemRequest();
req.setWorkitemId(workItemId);
req.setAction(action);
Approval.ProcessResult res = Approval.process(req);
...
}
var hash = window.location.hash;
var myStartSymbol = decodeURIComponent(hash.substring(1, hash.length));
myModule.config(function($interpolateProvider){
$interpolateProvider.startSymbol(myStartSymbol);
});
...
public String inputValue {
get { return inputValue; }
set { inputValue = value; }
}
...
String queryString = 'SELECT Id FROM Contact WHERE (IsDeleted = false AND Name like \'%' + inputValue + '%\')';
result = Database.query(queryString);
...
SELECT Id FROM Contact WHERE (IsDeleted = false AND Name like '%inputValue%')
inputValue
沒有包含單引號字元的時候,查詢才會正確執行。如果攻擊者為 inputValue
輸入字串 name') OR (Name like '%
,那麼查詢將會變更為:
SELECT Id FROM Contact WHERE (IsDeleted = false AND Name like '%name') OR (Name like '%%')
name') OR (Name like '%
會使 where 子句使用 LIKE '%%'
條件,以強制查詢輸出所有可能的 ID 值,因為此查詢在邏輯上可等同於以下較簡化的查詢:
SELECT Id FROM Contact WHERE ... OR (Name like '%%')
...
public String inputValue {
get { return inputValue; }
set { inputValue = value; }
}
...
String queryString = 'Name LIKE \'%' + inputValue + '%\'';
String searchString = 'Acme';
String searchQuery = 'FIND :searchString IN ALL FIELDS RETURNING Contact (Id WHERE ' + queryString + ')';
List<List<SObject>> results = Search.query(searchQuery);
...
String searchQuery = 'FIND :searchString IN ALL FIELDS RETURNING Contact (Id WHERE Name LIKE '%' + inputValue + '%')';
inputValue
沒有包含單引號字元的時候,查詢才會正確執行。如果攻擊者為 inputValue
輸入字串 1%' OR Name LIKE '
,那麼查詢將會變更為:
String searchQuery = 'FIND :searchString IN ALL FIELDS RETURNING Contact (Id WHERE Name LIKE '%1%' OR Name LIKE '%%')';
OR Name like '%%'
會使 where 子句使用 LIKE '%%'
條件,以強制查詢輸出所有包含「對應」片語的記錄,因為此查詢在邏輯上可等同於以下較簡化的查詢:
FIND 'map*' IN ALL FIELDS RETURNING Contact (Id WHERE Name LIKE '%%')
String beans = getBeanDefinitionFromUser();
GenericApplicationContext ctx = new GenericApplicationContext();
XmlBeanDefinitionReader xmlReader = new XmlBeanDefinitionReader(ctx);
xmlReader.loadBeanDefinitions(new UrlResource(beans));
ctx.refresh();
<web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="3.0"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" metadata-complete="true">
...
<context-param>
<param-name>defaultHtmlEscape</param-name>
<param-value>false</param-value>
</context-param>
...
</web-app>
...
v_account = request->get_form_field( 'account' ).
v_reference = request->get_form_field( 'ref_key' ).
CONCATENATE `user = '` sy-uname `'` INTO cl_where.
IF v_account IS NOT INITIAL.
CONCATENATE cl_where ` AND account = ` v_account INTO cl_where SEPARATED BY SPACE.
ENDIF.
IF v_reference IS NOT INITIAL.
CONCATENATE cl_where "AND ref_key = `" v_reference "`" INTO cl_where.
ENDIF.
SELECT *
FROM invoice_items
INTO CORRESPONDING FIELDS OF TABLE itab_items
WHERE (cl_where).
...
SELECT *
FROM invoice_items
INTO CORRESPONDING FIELDS OF TABLE itab_items
WHERE user = sy-uname
AND account = <account>
AND ref_key = <reference>.
"abc` OR MANDT NE `+"
,為 v_account 輸入字串「1000」,那麼查詢將會變更為:
SELECT *
FROM invoice_items
INTO CORRESPONDING FIELDS OF TABLE itab_items
WHERE user = sy-uname
AND account = 1000
AND ref_key = `abc` OR MANDT NE `+`.
OR MANDT NE `+`
條件會導致 WHERE
子句永遠評估為 true,因為用戶端欄位永遠不可能等於文字 +,所以此查詢邏輯上可等同於以下較簡化的查詢:
SELECT * FROM invoice_items
INTO CORRESPONDING FIELDS OF TABLE itab_items.
invoice_items
表中的項目,而不考慮指定的使用者為何。
PARAMETERS: p_street TYPE string,
p_city TYPE string.
Data: v_sql TYPE string,
stmt TYPE REF TO CL_SQL_STATEMENT.
v_sql = "UPDATE EMP_TABLE SET ".
"Update employee address. Build the update statement with changed details
IF street NE p_street.
CONCATENATE v_sql "STREET = `" p_street "`".
ENDIF.
IF city NE p_city.
CONCATENATE v_sql "CITY = `" p_city "`".
ENDIF.
l_upd = stmt->execute_update( v_sql ).
"ABC` SALARY = `1000000"
,則應用程式允許使用修訂的薪資更新資料庫!
...
var params:Object = LoaderInfo(this.root.loaderInfo).parameters;
var username:String = String(params["username"]);
var itemName:String = String(params["itemName"]);
var query:String = "SELECT * FROM items WHERE owner = " + username + " AND itemname = " + itemName;
stmt.sqlConnection = conn;
stmt.text = query;
stmt.execute();
...
SELECT * FROM items
WHERE owner = <userName>
AND itemname = <itemName>;
itemName
沒有包含單引號字元的時候,查詢才會正確執行。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串「name' OR 'a'='a
」,那麼查詢將變成以下內容:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name' OR 'a'='a';
OR 'a'='a'
會使 where 子句的評估永遠為 True,所以此查詢在邏輯上可等同於以下較簡化的查詢:
SELECT * FROM items;
items
表中的項目,而不考慮指定的擁有者為何。Example 1
中執行的效果。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串「name'; DELETE FROM items; --
」,那麼查詢將變成以下兩個查詢:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
--'
Example 1
中的方法。如果攻擊者輸入「name'); DELETE FROM items; SELECT * FROM items WHERE 'a'='a
」字串,將會建立以下三個有效的陳述式:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
SELECT * FROM items WHERE 'a'='a';
owner
與目前已驗證使用者名稱相符的項目。
...
string userName = ctx.getAuthenticatedUserName();
string query = "SELECT * FROM items WHERE owner = '"
+ userName + "' AND itemname = '"
+ ItemName.Text + "'";
sda = new SqlDataAdapter(query, conn);
DataTable dt = new DataTable();
sda.Fill(dt);
...
SELECT * FROM items
WHERE owner = <userName>
AND itemname = <itemName>;
itemName
沒有包含單引號字元的時候,查詢才會正確執行。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串「name' OR 'a'='a
」,那麼查詢將變成以下內容:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name' OR 'a'='a';
OR 'a'='a'
會使 where 子句的評估永遠為 True,所以此查詢在邏輯上可等同於以下較簡化的查詢:
SELECT * FROM items;
items
表中的項目,而不考慮指定的擁有者為何。Example 1
中執行的效果。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串「name'); DELETE FROM items; --
」,那麼查詢將變成以下兩個查詢:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
--'
Example 1
中的方法。如果攻擊者輸入「name'); DELETE FROM items; SELECT * FROM items WHERE 'a'='a
」字串,將會建立以下三個有效的陳述式:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
SELECT * FROM items WHERE 'a'='a';
範例 2:或者,也可以使用下列程式碼利用 SQLite 取得相似的結果:
...
ctx.getAuthUserName(&userName); {
CString query = "SELECT * FROM items WHERE owner = '"
+ userName + "' AND itemname = '"
+ request.Lookup("item") + "'";
dbms.ExecuteSQL(query);
...
...
sprintf (sql, "SELECT * FROM items WHERE owner='%s' AND itemname='%s'", username, request.Lookup("item"));
printf("SQL to execute is: \n\t\t %s\n", sql);
rc = sqlite3_exec(db,sql, NULL,0, &err);
...
SELECT * FROM items
WHERE owner = <userName>
AND itemname = <itemName>;
itemName
沒有包含單引號字元的時候,查詢才會正確執行。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串「name' OR 'a'='a
」,那麼查詢將變成以下內容:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name' OR 'a'='a';
OR 'a'='a'
會使 where 子句的評估永遠為 True,所以此查詢在邏輯上可等同於以下較簡化的查詢:
SELECT * FROM items;
items
表中的項目,而不考慮指定的擁有者為何。Example 1
中執行的效果。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串「name'); DELETE FROM items; --
」,那麼查詢將變成以下兩個查詢:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
--'
Example 1
中的方法。如果攻擊者輸入「name'); DELETE FROM items; SELECT * FROM items WHERE 'a'='a
」字串,將會建立以下三個有效的陳述式:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
SELECT * FROM items WHERE 'a'='a';
...
ACCEPT USER.
ACCEPT ITM.
MOVE "SELECT * FROM items WHERE owner = '" TO QUERY1.
MOVE "' AND itemname = '" TO QUERY2.
MOVE "'" TO QUERY3.
STRING
QUERY1, USER, QUERY2, ITM, QUERY3 DELIMITED BY SIZE
INTO QUERY
END-STRING.
EXEC SQL
EXECUTE IMMEDIATE :QUERY
END-EXEC.
...
SELECT * FROM items
WHERE owner = <userName>
AND itemname = <itemName>;
itemName
沒有包含單引號字元的時候,查詢才會正確執行。如果使用者名稱為 wiley
的攻擊者在 itm
中輸入字串「name' OR 'a'='a
」,那麼查詢將變成以下內容:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name' OR 'a'='a';
OR 'a'='a'
會使 where 子句的評估永遠為 True,所以此查詢在邏輯上可等同於以下較簡化的查詢:
SELECT * FROM items;
items
表中的項目,而不考慮指定的擁有者為何。Example 1
中建構和執行之查詢所帶來的效果。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串「name'; DELETE FROM items; --
」,那麼查詢將變成以下兩個查詢:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
--'
Example 1
中的方法。如果攻擊者輸入「name'); DELETE FROM items; SELECT * FROM items WHERE 'a'='a
」字串,將會建立以下三個有效的陳述式:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
SELECT * FROM items WHERE 'a'='a';
...
<cfquery name="matchingItems" datasource="cfsnippets">
SELECT * FROM items
WHERE owner='#Form.userName#'
AND itemId=#Form.ID#
</cfquery>
...
SELECT * FROM items
WHERE owner = <userName>
AND itemId = <ID>;
Form.ID
沒有包含單引號字元的時候,查詢才會正確執行。如果使用者名稱為 wiley
的攻擊者在 Form.ID
中輸入字串「name' OR 'a'='a
」,那麼查詢將變成以下內容:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemId = 'name' OR 'a'='a';
OR 'a'='a'
會使 where 子句的評估永遠為 True,所以此查詢在邏輯上可等同於以下較簡化的查詢:
SELECT * FROM items;
items
表中的項目,而不考慮指定的擁有者為何。Example 1
中執行的效果。如果使用者名稱為 hacker
的攻擊者在 Form.ID
中輸入字串「hacker'); DELETE FROM items; --
」,那麼查詢將變成以下兩個查詢:
SELECT * FROM items
WHERE owner = 'hacker'
AND itemId = 'name';
DELETE FROM items;
--'
Example 1
中的方法。如果攻擊者輸入「name'); DELETE FROM items; SELECT * FROM items WHERE 'a'='a
」字串,將會建立以下三個有效的陳述式:
SELECT * FROM items
WHERE owner = 'hacker'
AND itemId = 'name';
DELETE FROM items;
SELECT * FROM items WHERE 'a'='a';
...
final server = await HttpServer.bind('localhost', 18081);
server.listen((request) async {
final headers = request.headers;
final userName = headers.value('userName');
final itemName = headers.value('itemName');
final query = "SELECT * FROM items WHERE owner = '"
+ userName! + "' AND itemname = '"
+ itemName! + "'";
db.query(query);
}
...
SELECT * FROM items
WHERE owner = <userName>
AND itemname = <itemName>;
itemName
沒有包含單引號字元的時候,查詢才會正確執行。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串 name' OR 'a'='a
,那麼查詢將變成以下內容:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name' OR 'a'='a';
OR 'a'='a'
會使 where 子句的評估永遠為 True,所以此查詢在邏輯上可等同於以下較簡化的查詢:
SELECT * FROM items;
items
表中的項目,而不考慮指定的擁有者為何。Example 1
中執行的效果。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串「name'; DELETE FROM items; --
」,那麼查詢將變成以下兩個查詢:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
--'
Example 1
中所示的訣竅進行攻擊。如果攻擊者輸入「name'); DELETE FROM items; SELECT * FROM items WHERE 'a'='a
」字串,將會建立以下三個有效的陳述式:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
SELECT * FROM items WHERE 'a'='a';
...
rawQuery := request.URL.Query()
username := rawQuery.Get("userName")
itemName := rawQuery.Get("itemName")
query := "SELECT * FROM items WHERE owner = " + username + " AND itemname = " + itemName + ";"
db.Exec(query)
...
SELECT * FROM items
WHERE owner = <userName>
AND itemname = <itemName>;
itemName
不包含單引號字元時,查詢才會正確運作。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串 name' OR 'a'='a
,那麼查詢將變成以下內容:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name' OR 'a'='a';
OR 'a'='a'
會使 where 子句的評估永遠為 True,所以此查詢在邏輯上可等同於以下較簡化的查詢:
SELECT * FROM items;
items
表中的項目,而不考慮指定的擁有者為何。Example 1
中執行的效果。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串「name'; DELETE FROM items; --
」,那麼查詢將變成以下兩個查詢:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
--'
Example 1
中所示的訣竅進行攻擊。如果攻擊者輸入 "name'; DELETE FROM items; SELECT * FROM items WHERE 'a'='a
" 字串,將會建立以下三個有效的陳述式:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
SELECT * FROM items WHERE 'a'='a';
...
String userName = ctx.getAuthenticatedUserName();
String itemName = request.getParameter("itemName");
String query = "SELECT * FROM items WHERE owner = '"
+ userName + "' AND itemname = '"
+ itemName + "'";
ResultSet rs = stmt.execute(query);
...
SELECT * FROM items
WHERE owner = <userName>
AND itemname = <itemName>;
itemName
沒有包含單引號字元的時候,查詢才會正確執行。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串「name' OR 'a'='a
」,那麼查詢將變成以下內容:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name' OR 'a'='a';
OR 'a'='a'
會使 where 子句的評估永遠為 True,所以此查詢在邏輯上可等同於以下較簡化的查詢:
SELECT * FROM items;
items
表中的項目,而不考慮指定的擁有者為何。Example 1
中執行的效果。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串「name'; DELETE FROM items; --
」,那麼查詢將變成以下兩個查詢:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
--'
Example 1
中的方法。如果攻擊者輸入「name'); DELETE FROM items; SELECT * FROM items WHERE 'a'='a
」字串,將會建立以下三個有效的陳述式:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
SELECT * FROM items WHERE 'a'='a';
Example 1
以適用於 Android 平台。
...
PasswordAuthentication pa = authenticator.getPasswordAuthentication();
String userName = pa.getUserName();
String itemName = this.getIntent().getExtras().getString("itemName");
String query = "SELECT * FROM items WHERE owner = '"
+ userName + "' AND itemname = '"
+ itemName + "'";
SQLiteDatabase db = this.openOrCreateDatabase("DB", MODE_PRIVATE, null);
Cursor c = db.rawQuery(query, null);
...
...
var username = document.form.username.value;
var itemName = document.form.itemName.value;
var query = "SELECT * FROM items WHERE owner = " + username + " AND itemname = " + itemName + ";";
db.transaction(function (tx) {
tx.executeSql(query);
}
)
...
SELECT * FROM items
WHERE owner = <userName>
AND itemname = <itemName>;
itemName
沒有包含單引號字元的時候,查詢才會正確執行。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串「name' OR 'a'='a
」,那麼查詢將變成以下內容:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name' OR 'a'='a';
OR 'a'='a'
會使 where 子句的評估永遠為 True,所以此查詢在邏輯上可等同於以下較簡化的查詢:
SELECT * FROM items;
items
表中的項目,而不考慮指定的擁有者為何。Example 1
中執行的效果。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串「name'; DELETE FROM items; --
」,那麼查詢將變成以下兩個查詢:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
--'
Example 1
中的方法。如果攻擊者輸入「name'); DELETE FROM items; SELECT * FROM items WHERE 'a'='a
」字串,將會建立以下三個有效的陳述式:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
SELECT * FROM items WHERE 'a'='a';
...
$userName = $_SESSION['userName'];
$itemName = $_POST['itemName'];
$query = "SELECT * FROM items WHERE owner = '$userName' AND itemname = '$itemName';";
$result = mysql_query($query);
...
SELECT * FROM items
WHERE owner = <userName>
AND itemname = <itemName>;
itemName
沒有包含單引號字元的時候,查詢才會正確執行。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串「name' OR 'a'='a
」,那麼查詢將變成以下內容:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name' OR 'a'='a';
OR 'a'='a'
會使 where 子句的評估永遠為 True,所以此查詢在邏輯上可等同於以下較簡化的查詢:
SELECT * FROM items;
items
表中的項目,而不考慮指定的擁有者為何。Example 1
中執行的效果。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串「name'; DELETE FROM items; --
」,那麼查詢將變成以下兩個查詢:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
--'
Example 1
中的方法。如果攻擊者輸入「name'); DELETE FROM items; SELECT * FROM items WHERE 'a'='a
」字串,將會建立以下三個有效的陳述式:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
SELECT * FROM items WHERE 'a'='a';
procedure get_item (
itm_cv IN OUT ItmCurTyp,
usr in varchar2,
itm in varchar2)
is
open itm_cv for ' SELECT * FROM items WHERE ' ||
'owner = '''|| usr || '''' ||
' AND itemname = ''' || itm || '''';
end get_item;
SELECT * FROM items
WHERE owner = <userName>
AND itemname = <itemName>;
itemName
沒有包含單引號字元的時候,查詢才會正確執行。如果一個使用者名稱為 wiley
的攻擊者為 itm
輸入字串「name' OR 'a'='a
」,那麼查詢將變成:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name' OR 'a'='a';
OR 'a'='a'
會使 where 子句的評估永遠為 True,所以此查詢在邏輯上可等同於以下較簡化的查詢:
SELECT * FROM items;
items
表中的項目,而不考慮指定的擁有者為何。Example 1
中建構和執行之查詢所帶來的效果。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串「name'; DELETE FROM items; --
」,那麼查詢將變成以下兩個查詢:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
--'
Example 1
中的方法。如果攻擊者輸入「name'); DELETE FROM items; SELECT * FROM items WHERE 'a'='a
」字串,將會建立以下三個有效的陳述式:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
SELECT * FROM items WHERE 'a'='a';
...
userName = req.field('userName')
itemName = req.field('itemName')
query = "SELECT * FROM items WHERE owner = ' " + userName +" ' AND itemname = ' " + itemName +"';"
cursor.execute(query)
result = cursor.fetchall()
...
SELECT * FROM items
WHERE owner = <userName>
AND itemname = <itemName>;
itemName
沒有包含單引號字元的時候,查詢才會正確執行。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串「name' OR 'a'='a
」,那麼查詢將變成以下內容:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name' OR 'a'='a';
OR 'a'='a'
會使 where 子句的評估永遠為 True,所以此查詢在邏輯上可等同於以下較簡化的查詢:
SELECT * FROM items;
items
表中的項目,而不考慮指定的擁有者為何。Example 1
中執行的效果。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串「name'; DELETE FROM items; --
」,那麼查詢將變成以下兩個查詢:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
--'
Example 1
中的方法。如果攻擊者輸入「name'); DELETE FROM items; SELECT * FROM items WHERE 'a'='a
」字串,將會建立以下三個有效的陳述式:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
SELECT * FROM items WHERE 'a'='a';
...
userName = getAuthenticatedUserName()
itemName = params[:itemName]
sqlQuery = "SELECT * FROM items WHERE owner = '#{userName}' AND itemname = '#{itemName}'"
rs = conn.query(sqlQuery)
...
SELECT * FROM items
WHERE owner = <userName>
AND itemname = <itemName>;
itemName
沒有包含單引號字元的時候,查詢才會正確執行。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串「name' OR 'a'='a
」,那麼查詢將變成以下內容:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name' OR 'a'='a';
OR 'a'='a'
會使 where 子句的評估永遠為 True,所以此查詢在邏輯上可等同於以下較簡化的查詢:
SELECT * FROM items;
items
表中的項目,而不考慮指定的擁有者為何。
...
id = params[:id]
itemName = Mysql.escape_string(params[:itemName])
sqlQuery = "SELECT * FROM items WHERE id = #{userName} AND itemname = '#{itemName}'"
rs = conn.query(sqlQuery)
...
SELECT * FROM items WHERE id=<id> AND itemname = <itemName>;
itemName
內指定單引號的攻擊者,並且似乎遏止了 SQL injection 弱點。不過,由於 Ruby 不是靜態輸入的語言,因此,雖然 id
預期為某些變數的整數,但由於其是從使用者輸入指定的,因此也未必是數字。如果攻擊者可將 id
的值變更為 1 OR id!=1--
,則由於沒有檢查 id
實際上是否為數字,SQL 查詢現在變為:
SELECT * FROM items WHERE id=1 OR id!=1-- AND itemname = 'anyValue';
SELECT * FROM items WHERE id=1 OR id!=1;
id
的值是否等於 1,顯然該值等於表格內的全部內容。
def doSQLQuery(value:String) = Action.async { implicit request =>
val result: Future[Seq[User]] = db.run {
sql"select * from users where name = '#$value'".as[User]
}
...
}
SELECT * FROM users
WHERE name = <userName>
userName
沒有包含單引號字元的時候,查詢才會正確執行。 如果使用者名稱為 wiley
的攻擊者在 userName
中輸入字串「name' OR 'a'='a
」,那麼查詢將變成以下內容:
SELECT * FROM users
WHERE name = 'name' OR 'a'='a';
OR 'a'='a'
會使 where 子句的評估永遠為 True,所以此查詢在邏輯上可等同於以下較簡化的查詢:
SELECT * FROM users;
users
表格中的所有項目,無論它們的指定使用者是誰。owner
與目前已驗證使用者名稱相符的項目。
...
let queryStatementString = "SELECT * FROM items WHERE owner='\(username)' AND itemname='\(item)'"
var queryStatement: OpaquePointer? = nil
if sqlite3_prepare_v2(db, queryStatementString, -1, &queryStatement, nil) == SQLITE_OK {
if sqlite3_step(queryStatement) == SQLITE_ROW {
...
}
}
...
SELECT * FROM items
WHERE owner = '<userName>'
AND itemname = '<itemName>'
itemName
沒有包含單引號字元的時候,查詢才會正確執行。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串「name' OR 'a'='a
」,那麼查詢將變成以下內容:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name' OR 'a'='a';
OR 'a'='a'
會使 where 子句的評估永遠為 True,所以此查詢在邏輯上可等同於以下較簡化的查詢:
SELECT * FROM items;
items
表中的項目,而不考慮指定的擁有者為何。Example 1
中執行的效果。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串「name'); DELETE FROM items; --
」,那麼查詢將變成以下兩個查詢:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
--'
Example 1
中的方法。如果攻擊者輸入「name'); DELETE FROM items; SELECT * FROM items WHERE 'a'='a
」字串,將會建立以下三個有效的陳述式:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
SELECT * FROM items WHERE 'a'='a';
...
username = Session("username")
itemName = Request.Form("itemName")
strSQL = "SELECT * FROM items WHERE owner = '"& userName &"' AND itemname = '" & itemName &"'"
objRecordSet.Open strSQL, strConnect, adOpenDynamic, adLockOptimistic, adCmdText
...
SELECT * FROM items
WHERE owner = <userName>
AND itemname = <itemName>;
itemName
沒有包含單引號字元的時候,查詢才會正確執行。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串「name' OR 'a'='a
」,那麼查詢將變成以下內容:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name' OR 'a'='a';
OR 'a'='a'
會使 where 子句的評估永遠為 True,所以此查詢在邏輯上可等同於以下較簡化的查詢:
SELECT * FROM items;
items
表中的項目,而不考慮指定的擁有者為何。Example 1
中執行的效果。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串「name'; DELETE FROM items; --
」,那麼查詢將變成以下兩個查詢:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
--'
Example 1
中的方法。如果攻擊者輸入「name'); DELETE FROM items; SELECT * FROM items WHERE 'a'='a
」字串,將會建立以下三個有效的陳述式:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name';
DELETE FROM items;
SELECT * FROM items WHERE 'a'='a';
owner
與目前已驗證使用者名稱相符的項目。
...
string userName = ctx.getAuthenticatedUserName();
string queryString = "SELECT * FROM items WHERE owner = '"
+ userName + "' AND itemname = '"
+ ItemName.Text + "'";
SimpleQuery<Item> queryObject = new SimpleQuery(queryString);
Item[] items = (Item[])queryObject.Execute(query);
...
SELECT * FROM items
WHERE owner = <userName>
AND itemname = <itemName>;
itemName
沒有包含單引號字元的時候,查詢才會正確執行。如果使用者名稱為 wiley
的攻擊者在 itemName
中輸入字串「name' OR 'a'='a
」,那麼查詢將變成以下內容:
SELECT * FROM items
WHERE owner = 'wiley'
AND itemname = 'name' OR 'a'='a';
OR 'a'='a'
會使 where 子句的評估永遠為 True,所以此查詢在邏輯上可等同於以下較簡化的查詢:
SELECT * FROM items;
items
表中的項目,而不考慮指定的擁有者為何。