GHSA-c38w-74pg-36hr — rsa
MEDIUMGHSA-c38w-74pg-36hr is a medium-severity (CVSS 5.9) CWE-385 vulnerability in rsa. No vendor fix is recorded yet; mitigation options are listed below.
Marvin Attack: potential key recovery through timing sidechannels
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-c38w-74pg-36hr.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-c38w-74pg-36hr plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
rsaReal-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
Due to a non-constant-time implementation, information about the private key is leaked through timing information which is observable over the network. An attacker may be able to use that information to recover the key.
Patches
No patch is yet available, however work is underway to migrate to a fully constant-time implementation.
Workarounds
The only currently available workaround is to avoid using the rsa crate in settings where attackers are able to observe timing information, e.g. local use on a non-compromised computer is fine.
References
This vulnerability was discovered as part of the "Marvin Attack", which revealed several implementations of RSA including OpenSSL had not properly mitigated timing sidechannel attacks.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | rsa | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rsa, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of rsa has shipped for GHSA-c38w-74pg-36hr yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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-c38w-74pg-36hr can be triaged on real exposure rather than presence alone.
Tailored to GHSA-c38w-74pg-36hr. 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-c38w-74pg-36hr in your dependencies?
O3 Security finds GHSA-c38w-74pg-36hr across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.