tough timestamp metadata is cached when it fails snapshot rollback checkGHSA-76g3-38jv-wxh4
MEDIUMFix: awslabs/tough@9b400e1GHSA-76g3-38jv-wxh4 is a medium-severity (CVSS 4.2) CWE-1025 vulnerability in tough. A fix is available for tough — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-76g3-38jv-wxh4.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
toughReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
Summary
TUF repositories use the timestamp role to protect against rollback events by enabling an automated process to periodically sign the role's metadata. While tough will ensure that the version of snapshot metadata in new timestamp metadata files was always greater than or equal to the previously trusted version, it will only do so after persisting the timestamp metadata to its cache.
Impact
If the tough client successfully detects a rollback event in which timestamp metadata contains outdated snapshot metadata, the invalid timestamp metadata will still be persisted to cache as trusted. tough may then subsequently incorrectly identify valid timestamp metadata as being rolled back, preventing the client from consuming valid updates.
Impacted versions: < v0.20.0
Patches
A fix for this issue is available in tough version 0.20.0 and later. Customers are advised to upgrade to version 0.20.0 or later and ensure any forked or derivative code is patched to incorporate the new fixes.
Workarounds
There is no recommended work around. Customers are advised to upgrade to version 0.20.0 or the latest version.
References
If you have any questions or comments about this advisory we ask that you contact AWS/Amazon Security via our vulnerability reporting page [1] or directly via email to [email protected]. Please do not create a public GitHub issue.
[1] Vulnerability reporting page: https://aws.amazon.com/security/vulnerability-reporting
Acknowledgement
These issues were identified by the TUF-Conformance project. We would like to thank Google for collaborating on this issue through the coordinated vulnerability disclosure process.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | tough | all versions | 0.20.0cargo update -p tough --precise 0.20.0 |
Affected Products
toughamazonDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tough, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update tough to 0.20.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-76g3-38jv-wxh4 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is GHSA-76g3-38jv-wxh4 in your dependencies?
Find it across crates.io, including transitive dependencies.