rustls-webpki: CPU denial of service in certificate path building
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
- Denial of service
- Confidentiality · integrity · availability
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- Fix status
- Fixed
No CVSS vector from any source. Fix status from GitHub. Impact type from CWE-400.
Summary
When this crate is given a pathological certificate chain to validate, it will spend CPU time exponential with the number of candidate certificates at each step of path building. Both TLS clients and TLS servers that accept client certificate are affected. We now give each path building operation a budget of 100 signature verifications. The original `webpki` crate is also affected, see [GHSA-8qv2-5vq6-g2g7](https://github.com/advisories/GHSA-8qv2-5vq6-g2g7). This was previously reported in the original crate <https://github.com/briansmith/webpki/issues/69> and re-reported to us recently.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | rustls-webpki (crates.io) | before 0.100.2 | 0.100.2 | Patch available | GHSA-fh2r-99q2-6mmg |
| — | rustls-webpki (crates.io) | 0.101.0 to before 0.101.4 | 0.101.4 | Patch available | GHSA-fh2r-99q2-6mmg |
- rustls-webpki (crates.io) Vendor— Affected before 0.100.2 Fixed in 0.100.2 Patch available GHSA-fh2r-99q2-6mmg
- rustls-webpki (crates.io) Vendor— Affected 0.101.0 to before 0.101.4 Fixed in 0.101.4 Patch available GHSA-fh2r-99q2-6mmg
Remediation
- Fix · GHSA-fh2r-99q2-6mmg rustls-webpki (crates.io) Fixed in 0.100.2 Advisory →
- Fix · GHSA-fh2r-99q2-6mmg rustls-webpki (crates.io) Fixed in 0.101.4 Advisory →
Timeline
- 2026-10-03 Threatist record created from GHSA-fh2r-99q2-6mmg
References
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences