Kingdom: Input Validation and Representation

Input validation and representation problems ares caused by metacharacters, alternate encodings and numeric representations. Security problems result from trusting input. The issues include: "Buffer Overflows," "Cross-Site Scripting" attacks, "SQL Injection," and many others.

Memcached Injection

C#/VB.NET/ASP.NET
Python

Abstract

Invoking a Memcached operation with input from an untrusted source might allow an attacker to introduce new key/value pairs in Memcached cache.

Explanation

Memcached injection errors occur when:

1. Data enters a program from an untrusted source.

2. The data is used to dynamically construct a Memcached key or value.

Example 1: The following code dynamically constructs a Memcached key.


    ...
            TextClient tc = (TextClient)Client.GetInstance("127.0.0.1", 11211, MemcachedFlags.TextProtocol);
            tc.Open();
            string id = txtID.Text;
            var result = get_page_from_somewhere();
            var response = Http_Response(result);
            tc.Set("req-" + id, response, TimeSpan.FromSeconds(1000));
            tc.Close();
            tc = null;
    ...

The operation that this code intends to execute follows:


    set req-1233 0 1000 n
    <serialized_response_instance>

Where n is length of the response.

However, because the operation is constructed dynamically by concatenating a constant key prefix and a user input string, an attacker may send the string ignore 0 0 1\r\n1\r\nset injected 0 3600 10\r\n0123456789\r\nset req-, then the operation becomes the following:


    set req-ignore 0 0 1
    1
    set injected 0 3600 10
    0123456789
    set req-1233 0 0 n
    <serialized_response_instance>

The preceding key will successfully add a new key/value pair in the cache injected=0123456789 and the attackers will be able to poison the cache.

References

[1] Novikov The New Page Of Injections Book: Memcached Injections

[2] Standards Mapping - Common Weakness Enumeration CWE ID 20

[3] Standards Mapping - Common Weakness Enumeration Top 25 2019 [3] CWE ID 020

[4] Standards Mapping - Common Weakness Enumeration Top 25 2020 [3] CWE ID 020

[5] Standards Mapping - Common Weakness Enumeration Top 25 2021 [4] CWE ID 020

[6] Standards Mapping - Common Weakness Enumeration Top 25 2022 [4] CWE ID 020

[7] Standards Mapping - Common Weakness Enumeration Top 25 2023 [6] CWE ID 020

[8] Standards Mapping - Common Weakness Enumeration Top 25 2024 [12] CWE ID 020

[9] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754

[10] Standards Mapping - FIPS200 SI

[11] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data

[12] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)

[13] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation

[14] Standards Mapping - OWASP Application Security Verification Standard 4.0 5.1.3 Input Validation Requirements (L1 L2 L3), 5.1.4 Input Validation Requirements (L1 L2 L3)

[15] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation

[16] Standards Mapping - OWASP Top 10 2004 A6 Injection Flaws

[17] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws

[18] Standards Mapping - OWASP Top 10 2010 A1 Injection

[19] Standards Mapping - OWASP Top 10 2013 A1 Injection

[20] Standards Mapping - OWASP Top 10 2017 A1 Injection

[21] Standards Mapping - OWASP Top 10 2021 A03 Injection

[22] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.6

[23] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2

[24] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1

[25] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1

[26] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1

[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1

[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1

[29] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4

[30] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0.1 Requirement 6.2.4

[31] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection

[32] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation

[33] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation

[34] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I

[35] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I

[36] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I

[37] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I

[38] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I

[39] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I

[40] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I

[41] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I

[42] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I

[43] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I

[44] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I

[45] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I

[46] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I

[47] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I

[48] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I

[49] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I

[50] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I

[51] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I

[52] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I

[53] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I

[54] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I

[55] Standards Mapping - Security Technical Implementation Guide Version 6.1 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I

[56] Standards Mapping - Web Application Security Consortium Version 2.00 Improper Input Handling (WASC-20)

desc.dataflow.dotnet.memcached_injection

Abstract

Invoking a Memcached operation with input coming from an untrusted source might allow an attacker to introduce new key/value pairs in Memcached cache.

Explanation


...
def store(request):
    id = request.GET['id']
    result = get_page_from_somewhere()
    response = HttpResponse(result)
    cache_time = 1800
    cache.set("req-" % id, response, cache_time)
    return response
...

The operation that this code intends to execute follows:


set req-1233 0 0 n
<serialized_response_instance>

However, because the operation is constructed dynamically by concatenating a constant key prefix and a user input string, an attacker may send the string ignore 0 0 1\r\n1\r\nset injected 0 3600 10\r\n0123456789\r\nset req-, then the operation becomes the following:


set req-ignore 0 0 1
1
set injected 0 3600 10
0123456789
set req-1233 0 0 n
<serialized_response_instance>

The preceding key will successfully add a new key/value pair in the cache injected=0123456789. Depending on the payload, attackers will be able to poison the cache or execute arbitrary code by injecting a Pickle-serialized payload that will execute arbitrary code upon deserialization.