VariantDraft

CWE-175Improper Handling of Mixed Encoding

Category: other

Description

The product does not properly handle when the same input uses several different (mixed) encodings.

Common consequences· 1

  • Integrity — Unexpected State

Potential mitigations· 4

  • [Architecture and Design]Avoid making decisions based on names of resources (e.g. files) if those resources can have alternate names.
  • [Implementation]
  • [Implementation]Use and specify an output encoding that can be handled by the downstream component that is reading the output. Common encodings include ISO-8859-1, UTF-7, and UTF-8. When an encoding is not specified, a downstream component may choose a different encoding, either by assuming a default encoding or automatically inferring which encoding is being used, which can be erroneous. When the encodings are inconsistent, the downstream component might treat some character or byte sequences as special, even if they are not special in the original encoding. Attackers might then be able to exploit this discrepancy and conduct injection attacks; they even might be able to bypass protection mechanisms that assume the original encoding is also being used by the downstream component.
  • [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.

References

  1. https://cwe.mitre.org/data/definitions/175.html

Related by meaning· 6

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

CWE
Improper Handling of Unicode Encoding
CWE
Improper Handling of Alternate Encoding
CWE
Improper Handling of Invalid Use of Special Elements
CWE
Improper Neutralization of Input Leaders
CWE
Improper Handling of Inconsistent Special Elements
CWE
Improper Handling of Additional Special Element
Sourced from MITRE CWE 4.20. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.