CVE-2022-31142 is a high-severity (CVSS 7.5) CWE-208 vulnerability in fastify-bearer-auth. A fix is available for fastify-bearer-auth — see the affected versions and patch details below.
Potential Timing Attack Vector in @fastify/bearer-auth
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- 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 CVE-2022-31142.
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
CVE-2022-31142 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 378,156 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
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, a proxy for how much of the ecosystem is exposed.
fastify-bearer-authnpm@fastify/bearer-authnpmDescription
Impact
fastify-bearer-auth does not securely use crypto.timingSafeEqual. A malicious attacker could estimate the length of one valid bearer token. According to the corresponding RFC 6750, the bearer token has only base64 valid characters, reducing the range of characters for a brute force attack.
All versions of fastify-bearer-auth are also affected.
Patches
We released:
- v8.0.1 with a fix for the Fastify v4 line
- v7.0.2 with a fix for the Fastify v3 line
Workarounds
There are no workarounds. Update your dependencies.
References
https://hackerone.com/reports/1633287
For more information
If you have any questions or comments about this advisory:
- Open an issue in https://github.com/fastify/fastify-bearer-auth
- Email us at [email protected]
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | fastify-bearer-auth | ≥ 5.0.1 | No fix |
| 📦npm | @fastify/bearer-auth | all versions | 7.0.2npm install @fastify/bearer-auth@7.0.2 |
| 📦npm | @fastify/bearer-auth | ≥ 8.0.0&&< 8.0.1 | 8.0.1npm install @fastify/bearer-auth@8.0.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for fastify-bearer-auth, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
No patched version of fastify-bearer-auth has shipped for CVE-2022-31142 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
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 CVE-2022-31142 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2022-31142. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2022-31142 in your dependencies?
O3 Security finds CVE-2022-31142 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.