CWE-421: Race Condition During Access to Alternate Channel
Official CWE-421 CWE context with Glexia analysis, remediation guidance, related CVEs, and ATT&CK context.
Glexia's Take
CWE-421: Race Condition During Access to Alternate Channel
Race Condition During Access to Alternate Channel represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Executive Impact
- Access Control: Gain Privileges or Assume Identity,Bypass Protection Mechanism
Developer Pattern
CWE-421 is the kind of defect developers can usually prevent with explicit validation, safer framework defaults, and tests that exercise hostile input or unsafe state transitions.
Confidence
high confidence from CWE-421, 4.20.
Official CWE Definition
CWE-421: Race Condition During Access to Alternate Channel
The product opens an alternate channel to communicate with an authorized user, but the channel is accessible to other actors.
This creates a race condition that allows an attacker to access the channel before the authorized user does.
Developer And Remediation Guidance
How teams prevent and detect this weakness
Causes
- Missing validation
- Unsafe defaults
- Insufficient authorization or memory-safety invariant
Remediation
- Use safe APIs
- Centralize the control
- Add regression tests
- Review logs and telemetry for attempted abuse
Detection
- Code review
- SAST
- DAST
- Focused regression tests
Mappings
Related CVEs, CWEs, and ATT&CK context
Related CWEs
ATT&CK Relevance
ATT&CK relevance is shown only when reviewed or responsibly inferred.