Red Hat Security Advisory: kernel security, bug fix, and enhancement update

1. Implementation

   For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.

2. Requirements

   Select a programming language that is not susceptible to these issues.

3. Implementation

   Check the results of all functions that return a value and verify that the value is non-null before acting upon it.

OWASP Cheat Sheets

• Logging (opens in a new tab)
• Error Handling (opens in a new tab)

OWASP ASVS 4.0.3

• V11.1.7 (opens in a new tab)

From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

1. Implementation · Input Validation

   Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.

2. Architecture and Design · Language Selection

   Use a language that provides appropriate memory abstractions.

OWASP Cheat Sheets

• XML Security (opens in a new tab)
• Mass Assignment (opens in a new tab)

OWASP ASVS 4.0.3

• V13.3.1 (opens in a new tab)
• V5.1.4 (opens in a new tab)
• V5.1.3 (opens in a new tab)

Attack patterns

• Overread Buffers (opens in a new tab)

From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

1. Implementation · Input Validation

   Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.

OWASP Cheat Sheets

• XML Security (opens in a new tab)
• Mass Assignment (opens in a new tab)

OWASP ASVS 4.0.3

• V13.3.1 (opens in a new tab)
• V5.1.4 (opens in a new tab)
• V5.1.3 (opens in a new tab)

From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

1. Architecture and Design

   Choose a language that provides automatic memory management.

2. Implementation

   When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.

OWASP Cheat Sheets

• XML Security (opens in a new tab)
• Mass Assignment (opens in a new tab)

OWASP ASVS 4.0.3

• V13.3.1 (opens in a new tab)
• V5.1.4 (opens in a new tab)
• V5.1.3 (opens in a new tab)

From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

1. Requirements · Language Selection

   Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.

2. Architecture and Design · Libraries or Frameworks

   Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.

3. Operation · Build and Compilation · Environment Hardening

   Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index…

OWASP Cheat Sheets

• Docker Security (opens in a new tab)
• XML Security (opens in a new tab)

OWASP ASVS 4.0.3

• V5.4.1 (opens in a new tab)
• V14.1.2 (opens in a new tab)
• V13.3.1 (opens in a new tab)

Attack patterns

• Buffer Overflow via Environment Variables (opens in a new tab)
• Overflow Buffers (opens in a new tab)
• Client-side Injection-induced Buffer Overflow (opens in a new tab)
• Filter Failure through Buffer Overflow (opens in a new tab)
• MIME Conversion (opens in a new tab)

From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

1. Requirements · Language Selection

   Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.

2. Architecture and Design · Libraries or Frameworks

   Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.

3. Operation · Build and Compilation · Environment Hardening

   Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index…

OWASP Cheat Sheets

• XML Security (opens in a new tab)
• Mass Assignment (opens in a new tab)

OWASP ASVS 4.0.3

• V13.3.1 (opens in a new tab)
• V5.1.4 (opens in a new tab)
• V5.1.3 (opens in a new tab)

From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

1. Implementation

   The most basic advice for TOCTOU vulnerabilities is to not perform a check before the use. This does not resolve the underlying issue of the execution of a function on a resource whose state and identity cannot be assured, but it does help to limit the false sense of security given by the check.

2. Implementation

   When the file being altered is owned by the current user and group, set the effective gid and uid to that of the current user and group when executing this statement.

3. Architecture and Design

   Limit the interleaving of operations on files from multiple processes.

OWASP Cheat Sheets

• Abuse Case (opens in a new tab)

OWASP ASVS 4.0.3

• V1.11.3 (opens in a new tab)
• V11.1.6 (opens in a new tab)
• V1.11.2 (opens in a new tab)

Attack patterns

• Leveraging Race Conditions via Symbolic Links (opens in a new tab)
• Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions (opens in a new tab)

From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

1. Architecture and Design · Language Selection

   Choose a language that provides automatic memory management.

2. Implementation · Attack Surface Reduction

   When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.

OWASP Cheat Sheets

• XML Security (opens in a new tab)
• Mass Assignment (opens in a new tab)

OWASP ASVS 4.0.3

• V13.3.1 (opens in a new tab)
• V5.1.4 (opens in a new tab)
• V5.1.3 (opens in a new tab)

From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

1. Implementation

   Explicitly initialize the resource before use. If this is performed through an API function or standard procedure, follow all specified steps.

2. Implementation

   Pay close attention to complex conditionals that affect initialization, since some branches might not perform the initialization.

3. Implementation

   Avoid race conditions (CWE-362) during initialization routines.

From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

1. Implementation

   Only call matching memory management functions. Do not mix and match routines. For example, when you allocate a buffer with malloc(), dispose of the original pointer with free().

2. Implementation

   When programming in C++, consider using smart pointers provided by the boost library to help correctly and consistently manage memory.

3. Architecture and Design · Libraries or Frameworks

   Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.

From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

1. Implementation

   If the assertion statement is required (e.g., for security or reliability), change the invoking code to avoid the conditions that trigger the assertion.

2. Implementation

   Consider changing the assertion to some other less "fatal" error. This might not be easy to implement, since other code may be needed to handle the error.

3. Implementation

   Make sensitive open/close operations non-reachable from directly user-controlled data (e.g. open/close resources)

From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

1. Implementation

   Change the code's logic so that the resource is only closed once. This might require simplifying or refactoring. This fix can be simple to do in small code blocks, but more difficult when multiple closes are buried within complex conditionals.

2. Implementation · Refactoring

   It can be effective to implement a flag that is (1) set when the resource is opened, (2) cleared when it is closed, and (3) checked before closing. This approach can be useful when there are disparate cases in which closes must be performed.

3. Implementation · Refactoring

   When closing a resource, set the resource's associated variable to NULL or equivalent value for the given language. Some APIs will ignore this null value without causing errors.

From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

1. Implementation

   When allocating a buffer for the purpose of transforming, converting, or encoding an input, allocate enough memory to handle the largest possible encoding. For example, in a routine that converts "&" characters to "&" for HTML entity encoding, the output buffer needs to be at least 5 times as large as the input…

2. Implementation

   Understand the programming language's underlying representation and how it interacts with numeric calculation (CWE-681). Pay close attention to byte size discrepancies, precision, signed/unsigned distinctions, truncation, conversion and casting between types, "not-a-number" calculations, and how the language handles…

3. Implementation · Input Validation

   Perform input validation on any numeric input by ensuring that it is within the expected range. Enforce that the input meets both the minimum and maximum requirements for the expected range.

Attack patterns

• Overflow Buffers (opens in a new tab)
• Buffer Overflow via Parameter Expansion (opens in a new tab)

From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

1. Implementation · Input Validation

   Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.

OWASP Cheat Sheets

• XML Security (opens in a new tab)
• Mass Assignment (opens in a new tab)

OWASP ASVS 4.0.3

• V13.3.1 (opens in a new tab)
• V5.1.4 (opens in a new tab)
• V5.1.3 (opens in a new tab)

From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

1. Architecture and Design

   Break up privileges between different modules, objects, or entities. Minimize the interfaces between modules and require strong access control between them.

OWASP Cheat Sheets

• Secure Design Principles (opens in a new tab)

From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).