CWE•Base•Draft•6 recent CVEs
CWE-76Improper Neutralization of Equivalent Special Elements
Description
The product correctly neutralizes certain special elements, but it improperly neutralizes equivalent special elements.
The product may have a fixed list of special characters it believes is complete. However, there may be alternate encodings, or representations that also have the same meaning. For example, the product may filter out a leading slash (/) to prevent absolute path names, but does not account for a tilde (~) followed by a user name, which on some *nix systems could be expanded to an absolute pathname. Alternately, the product might filter a dangerous "-e" command-line switch when calling an external program, but it might not account for "--exec" or other switches that have the same semantics.
Common consequences
- Other→Other
Potential mitigations
- RequirementsProgramming languages and supporting technologies might be chosen which are not subject to these issues.
- ImplementationUtilize an appropriate mix of allowlist and denylist parsing to filter equivalent special element syntax from all input.