How the CVE Works:
TUF repositories rely on the timestamp role to prevent rollback attacks by ensuring metadata freshness. The `tough` library enforces version checks for snapshot metadata in timestamp files, but only after caching the metadata. If an attacker provides outdated snapshot metadata, `tough` caches it before validation, leading to false rollback detection. This disrupts update integrity checks, preventing clients from accepting legitimate updates. The flaw persists in cached data, causing persistent validation failures until cache is cleared or patched.
DailyCVE Form:
Platform: TUF (tough)
Version: < 0.20.0
Vulnerability: Metadata Rollback
Severity: Medium
Date: 2023-XX-XX
What Undercode Say:
Exploitation:
- Attack Vector: Man-in-the-middle (MITM) or compromised repository server.
- Payload: Malicious timestamp metadata with older snapshot version.
3. Trigger: Client caches invalid metadata before validation.
Detection:
Check tough version: pip show tough | grep Version Log analysis for rollback warnings: grep "rollback detected" /var/log/tough.log
Mitigation:
1. Patch:
pip install --upgrade tough>=0.20.0
2. Cache Cleanup:
rm -rf /var/cache/tough/
3. Validation Script:
from tough.repository import Repository
repo = Repository("https://example.com/repo")
repo.refresh() Forces revalidation
Network Protections:
- Enforce HTTPS for metadata fetching.
- Use TUF’s `consistent_snapshot` feature.
Monitoring:
Monitor timestamp versions:
if timestamp.version < last_known_version:
alert("Rollback suspected!")
References:
No additional commentary beyond rules.
References:
Reported By: https://github.com/advisories/GHSA-76g3-38jv-wxh4
Extra Source Hub:
Undercode
