GHSA-rp9h-rf7g-hwgr — s2n-tls
Fix: aws/s2n-tls@493b771GHSA-rp9h-rf7g-hwgr is a security vulnerability in s2n-tls. A fix is available for s2n-tls — see the affected versions and patch details below.
s2n-tls has undefined behavior at process exit
Real-World Exposure
s2n-tlsReal-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
Impact
s2n-tls uses the Linux atexit function to register functions that clean up the global state when the process exits. In multi-threaded environments, the atexit handler may clean up state which is still in use by other threads. When this occurs, the exiting process may experience a segmentation fault or other undefined behavior.
Customers of AWS services do not need to take action. Applications using s2n-tls should upgrade to the most recent release of s2n-tls.
Impacted versions: < v1.5.9.
Patches
The patch commit 493b771 is included in s2n-tls v1.5.9 [1]
Workarounds
The atexit handler may be disabled by calling s2n_disable_atexit() prior to initializing s2n-tls. The atexit handler is off by default in the patched versions. For further details, refer to s2n-tls Usage Guide: Initialization and Teardown.
If you have any questions or comments about this advisory, we ask that you contact AWS/Amazon Security via our vulnerability reporting page [2] or directly via email to [email protected]. Please do not create a public GitHub issue.
[1] https://github.com/aws/s2n-tls/releases/tag/v1.5.9 [2] Vulnerability reporting page: https://aws.amazon.com/security/vulnerability-reporting
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | s2n-tls | all versions | 0.3.7cargo update -p s2n-tls --precise 0.3.7 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for s2n-tls, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update s2n-tls to 0.3.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-rp9h-rf7g-hwgr 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.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-rp9h-rf7g-hwgr can be triaged on real exposure rather than presence alone.
Tailored to GHSA-rp9h-rf7g-hwgr. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-rp9h-rf7g-hwgr in your dependencies?
O3 Security finds GHSA-rp9h-rf7g-hwgr across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.