CWE-150Improper Neutralization of Escape, Meta, or Control Sequences

Description

Common consequences· 1

• Integrity — Execute Unauthorized Code or Commands, Hide Activities, Unexpected State
  ANSI escape codes can be used for low-severity attacks such as changing the color of console output, but they can also be used to arbitrarily move the cursor, clear the screen, and make fake prompts inside the interactive CLI via malicious user input. In some contexts - depending on the functionality of the terminal in use - ANSI escape codes can be used to execute arbitrary code.

Potential mitigations· 5

• []Developers should anticipate that escape, meta and control characters/sequences will be injected/removed/manipulated in the input vectors of their product. Use an appropriate combination of denylists and allowlists to ensure only valid, expected and appropriate input is processed by the system.
• [Implementation]
• [Implementation]While it is risky to use dynamically-generated query strings, code, or commands that mix control and data together, sometimes it may be unavoidable. Properly quote arguments and escape any special characters within those arguments. The most conservative approach is to escape or filter all characters that do not pass an extremely strict allowlist (such as everything that is not alphanumeric or white space). If some special characters are still needed, such as white space, wrap each argument in quotes after the escaping/filtering step. Be careful of argument injection (CWE-88).
• [Implementation]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). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.
• [Implementation]When using output from an LLM, neutralize or strip escape codes before redirecting output to the terminal or other rendering engine that would process the codes. The neutralization could require that the character be printable and/or allowable whitespace, such as a carriage return or newline. Be deliberate about what to allow.

Related CAPEC attack patterns· 4

Exploits (incoming)4

(incoming)8

Related by meaning· 6

Nearest entities by semantic similarity across the cs-graph corpus.