CWE-176: Improper Handling of Unicode Encoding

What is CWE-176?

CWE-176 is Improper Handling of Unicode Encoding. The flaw arises when The product does not properly handle when an input contains Unicode encoding. The database currently holds 25 vulnerabilities mapped to CWE-176 and none of them are in the CISA Known Exploited Vulnerabilities catalog.

Analyzing data...

OWASP Top 10 Rank-
Related CVES (365 days)25
AbstractionVariant
Likelihood of exploit-

Vulnerabilities mapped to CWE-176

25 vulnerabilities

No data

No vulnerability data in CISA KEV for CWE-176

Official definition

ByMitre CWE

The product does not properly handle when an input contains Unicode encoding.

Characteristics

Modes of introduction

  • Implementation

Common consequences

ImpactScopeExplanation
Unexpected StateIntegrity-

Risk mitigations

  1. Input Validation · Architecture and DesignAvoid making decisions based on names of resources (e.g. files) if those resources can have alternate names.
  2. Input Validation · ImplementationAssume 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. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
  3. Input Validation · ImplementationInputs 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.

Representative vulnerabilities

Below are representative vulnerabilities related to this CWE, prioritized by severity.

Sources (2)
MITRE CWE
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