Improper Certificate Validation in Cosign (sigstore cosign)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.16 % · percentile 5 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Modified
Description
Cosign provides container signing, verification, and storage in an OCI registry for the sigstore project. Prior to version 1.5.2, Cosign can be manipulated to claim that an entry for a signature exists in the Rekor transparency log even if it doesn't. This requires the attacker to have pull and push permissions for the signature in OCI. This can happen with both standard signing with a keypair and "keyless signing" with Fulcio. If an attacker has access to the signature in OCI, they can manipulate cosign into believing the entry was stored in Rekor even though it wasn't. The vulnerability has been patched in v1.5.2 of Cosign. The `signature` in the `signedEntryTimestamp` provided by Rekor is now compared to the `signature` that is being verified. If these don't match, then an error is returned. If a valid bundle is copied to a different signature, verification should fail. Cosign output now only informs the user that certificates were verified if a certificate was in fact verified. There is currently no known workaround.
Weaknesses (CWE)
- CWE-295 — Improper Certificate Validation
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | LOW 3.3 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N | GitHub_M |
| CVSS 3.1 | LOW 3.3 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N | NVD · security-advisories@github.com (Secondary) |
| CVSS 3.1 | LOW 3.3 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N | NVD · nvd@nist.gov (Primary) |
| CVSS 2.0 | LOW 2.1 | AV:L/AC:L/Au:N/C:N/I:P/A:N | NVD · nvd@nist.gov (Primary) |
Advisories
- GHSA-ccxc-vr6p-4858 — Improper Certificate Validation in Cosign
- GO-2022-0326 — Improper certificate validation in github.com/sigstore/cosign
European references
- ENISA EUVD · EUVD-2022-0958
- GCVE · GCVE-0-2022-23649
Affected configurations (NVD CPE)
cpe:2.3:a:sigstore:cosign:*:*:*:*:*:*:*:*< 1.5.2
Affected products
| Product | Versions |
|---|---|
| sigstore · cosign | affected < 1.5.2 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |