Vulnerability · Published Sep 14, 2022 · Assigned by GitHub_M
CVE-2022-36056 Vulnerabilities with blob verification in sigstore cosign
Medium 5.5
In plain English
A medium-severity security flaw in cosign from sigstore. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 4% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Cosign is a project under the sigstore organization which aims to make signatures invisible infrastructure. In versions prior to 1.12.0 a number of vulnerabilities have been found in cosign verify-blob, where Cosign would successfully verify an artifact when verification should have failed. First a cosign bundle can be crafted to successfully verify a blob even if the embedded rekorBundle does not reference the given signature. Second, when providing identity flags, the email and issuer of a certificate is not checked when verifying a Rekor bundle, and the GitHub Actions identity is never checked. Third, providing an invalid Rekor bundle without the experimental flag results in a successful verification. And fourth an invalid transparency log entry will result in immediate success for verification. Details and examples of these issues can be seen in the GHSA-8gw7-4j42-w388 advisory linked. Users are advised to upgrade to 1.12.0. There are no known workarounds for these issues.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | cosign | 1.12.1-r0 | ALPINE-CVE-2022-36056 |
| Alpine:v3.21 | cosign | 1.12.1-r0 | ALPINE-CVE-2022-36056 |
| Alpine:v3.22 | cosign | 1.12.1-r0 | ALPINE-CVE-2022-36056 |
| Alpine:v3.23 | cosign | 1.12.1-r0 | ALPINE-CVE-2022-36056 |
| Alpine:v3.24 | cosign | 1.12.1-r0 | ALPINE-CVE-2022-36056 |
| Go | github.com/sigstore/cosign | 1.12.0 | GHSA-8gw7-4j42-w388 |
| Go | github.com/sigstore/cosign | 1.12.0 | GO-2022-0998 |
Affected products (as reported)
Weakness: CWE-347 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N