Red Hat Security Advisory: linux-sgx security update

1. Implementation

   By freezing the object prototype first (for example, Object.freeze(Object.prototype)), modification of the prototype becomes impossible.

2. Architecture and Design

   By blocking modifications of attributes that resolve to object prototype, such as proto or prototype, this weakness can be mitigated.

3. Implementation · Input Validation

   When handling untrusted objects, validating using a schema can be used.

OWASP Cheat Sheets

• Mass Assignment (opens in a new tab)

OWASP ASVS 4.0.3

• V5.1.2 (opens in a new tab)

Attack patterns

• Accessing Functionality Not Properly Constrained by ACLs (opens in a new tab)
• Exploiting Incorrectly Configured Access Control Security Levels (opens in a new tab)
• Manipulating User-Controlled Variables (opens in a new tab)

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

1. Requirements

   Clearly specify the minimum and maximum expectations for capabilities, and dictate which behaviors are acceptable when resource allocation reaches limits.

2. Architecture and Design

   Limit the amount of resources that are accessible to unprivileged users. Set per-user limits for resources. Allow the system administrator to define these limits. Be careful to avoid CWE-410.

3. Architecture and Design

   Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended.

OWASP Cheat Sheets

• Abuse Case (opens in a new tab)

OWASP ASVS 4.0.3

• V8.1.4 (opens in a new tab)
• V13.4.1 (opens in a new tab)
• V11.1.4 (opens in a new tab)

Attack patterns

• XML Ping of the Death (opens in a new tab)
• Exponential Data Expansion (opens in a new tab)
• Serialized Data Parameter Blowup (opens in a new tab)
• Serialized Data with Nested Payloads (opens in a new tab)
• Oversized Serialized Data Payloads (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

   For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks…

3. Implementation · Input Validation

   Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174).

OWASP Cheat Sheets

• Authorization (opens in a new tab)

OWASP ASVS 4.0.3

• V12.3.1 (opens in a new tab)

Attack patterns

• Path Traversal (opens in a new tab)
• Using Slashes and URL Encoding Combined to Bypass Validation Logic (opens in a new tab)
• Manipulating Web Input to File System Calls (opens in a new tab)
• Using Escaped Slashes in Alternate Encoding (opens in a new tab)
• Using Slashes in Alternate Encoding (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 · Separation of Privilege

   Follow the principle of least privilege when assigning access rights to entities in a software system.

OWASP Cheat Sheets

• Authorization (opens in a new tab)

Attack patterns

• Symlink Attack (opens in a new tab)
• Using Malicious Files (opens in a new tab)
• Leverage Executable Code in Non-Executable Files (opens in a new tab)
• Manipulating Web Input to File System Calls (opens in a new tab)

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