CVE-2022-23649

Improper Certificate Validation in Cosign

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.

Category

3.3
CVSS
Severity: Low
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.05%
Third-Party Advisory github.com Third-Party Advisory github.com
Affected: sigstore cosign
Published at:
Updated at:

References

Link Tags
https://github.com/sigstore/cosign/security/advisories/GHSA-ccxc-vr6p-4858 third party advisory
https://github.com/sigstore/cosign/commit/96d410a6580e4e81d24d112a0855c70ca3fb5b49 third party advisory patch

Frequently Asked Questions

What is the severity of CVE-2022-23649?
CVE-2022-23649 has been scored as a low severity vulnerability.
How to fix CVE-2022-23649?
To fix CVE-2022-23649, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2022-23649 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2022-23649 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2022-23649?
CVE-2022-23649 affects sigstore cosign.
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