Run static analysis (SAST) on the codebase looking for the unsafe pattern in the data flow.
Deprecated by MITRE
This CWE entry has been deprecated by MITRE. It is kept here for reference and backward compatibility with older links. Browse the active weaknesses catalogue for current guidance.
CWE-92 Base Deprecated
DEPRECATED: Improper Sanitization of Custom Special Characters
This deprecated entry originally flagged issues where custom or non-standard special characters weren't properly sanitized. It has been consolidated into the more comprehensive CWE-75: Failure to…
Definition
What is CWE-92?
This deprecated entry originally flagged issues where custom or non-standard special characters weren't properly sanitized. It has been consolidated into the more comprehensive CWE-75: Failure to Sanitize Special Elements.
This weakness was retired because it represented a specific example of a broader security problem. The original PLOVER taxonomy sometimes created narrow categories like this for completeness, but for effective vulnerability mapping, CWE now uses more general, flexible entries that better capture the root cause.
Developers should now reference CWE-75, which covers the failure to properly neutralize any special elements before use, including custom delimiters, escape sequences, or application-specific markup. This consolidation makes it easier to map real-world vulnerabilities and apply consistent defensive coding practices against injection-style attacks.
Real-world impact
Real-world CVEs caused by CWE-92
No public CVE references are linked to this CWE in MITRE's catalog yet.
How attackers exploit it
Step-by-step attacker path
- 1
Identify a code path that handles untrusted input without validation.
- 2
Craft a payload that exercises the unsafe behavior — injection, traversal, overflow, or logic abuse.
- 3
Deliver the payload through a normal request and observe the application's reaction.
- 4
Iterate until the response leaks data, executes attacker code, or escalates privileges.
Vulnerable code example
Vulnerable pseudo
MITRE has not published a code example for this CWE. The pattern below is illustrative — see Resources for canonical references.
// Example pattern — see MITRE for the canonical references.
function handleRequest(input) {
// Untrusted input flows directly into the sensitive sink.
return executeUnsafe(input);
} Secure code example
Secure pseudo
// Validate, sanitize, or use a safe API before reaching the sink.
function handleRequest(input) {
const safe = validateAndEscape(input);
return executeWithGuards(safe);
} What changed: the unsafe sink is replaced (or the input is validated/escaped) so the same payload no longer triggers the weakness.
Prevention checklist
How to prevent CWE-92
- Architecture Use safe-by-default frameworks and APIs that prevent the unsafe pattern from being expressible.
- Implementation Validate input at trust boundaries; use allowlists, not denylists.
- Implementation Apply the principle of least privilege to credentials, file paths, and runtime permissions.
- Testing Cover this weakness in CI: SAST rules + targeted unit tests for the data flow.
- Operation Monitor logs for the runtime signals listed in the next section.
Detection signals
How to detect CWE-92
Run dynamic application security testing against the live endpoint.
Watch runtime logs for unusual exception traces, malformed input, or authorization bypass attempts.
Code review: flag any new code that handles input from this surface without using the validated framework helpers.
CWE-92
Don't catalog this weakness. Prove it's reachable.
Plexicus turns CWE catalogs into evidence: every CWE-pattern is matched against your real code graph, reach is proven on a sandbox clone, and verified findings ship as reviewed PRs.
Frequently asked questions What is CWE-92?
How serious is CWE-92?
What languages or platforms are affected by CWE-92?
How can I prevent CWE-92?
How does Plexicus detect and fix CWE-92?
Where can I learn more about CWE-92?
Frequently asked questions
What is CWE-92?
This deprecated entry originally flagged issues where custom or non-standard special characters weren't properly sanitized. It has been consolidated into the more comprehensive CWE-75: Failure to Sanitize Special Elements.
How serious is CWE-92?
MITRE has not published a likelihood-of-exploit rating for this weakness. Treat it as medium-impact until your threat model proves otherwise.
What languages or platforms are affected by CWE-92?
MITRE has not specified affected platforms for this CWE — it can apply across most application stacks.
How can I prevent CWE-92?
Use safe-by-default frameworks, validate untrusted input at trust boundaries, and apply the principle of least privilege. Cover the data-flow signature in CI with SAST.
How does Plexicus detect and fix CWE-92?
Plexicus's SAST engine matches the data-flow signature for CWE-92 on every commit. When a match is found, our Codex Remedium agent opens a fix PR with the corrected code, tests, and a one-line summary for the reviewer.
Where can I learn more about CWE-92?
MITRE publishes the canonical definition at https://cwe.mitre.org/data/definitions/92.html. You can also reference OWASP and NIST documentation for adjacent guidance.
Related weaknesses
Weaknesses related to CWE-92
No related weaknesses indexed for this CWE.
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