CVE-2022-23649 Improper Certificate Validation in Cosign
Attackers with OCI permissions can bypass Rekor transparency log verification, falsely claiming signatures are logged when they are not.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-23649?
CVE-2022-23649 is a low-severity vulnerability in sigstore cosign, published on 18 Feb 2022. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-295
Which versions are affected by CVE-2022-23649?
4 open source packages ship an affected version, including github.com/sigstore/cosign and cosign. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/sigstore/cosign Go | All versions | 1.5.2 |
github.com/sigstore/cosign Go | All versions | 1.5.2 |
github.com/sigstore/cosign Go | All versions | 1.5.2 |
cosign Bitnami | All versions | 1.5.2 |
Linux distribution packages (1)
cosign openSUSE:Tumbleweed | All versions | 1.5.2-1.1 |
Products include Sigstore Cosign.
How do I fix CVE-2022-23649?
Upgrade github.com/sigstore/cosign to 1.5.2 or later.
Is CVE-2022-23649 being exploited?
There is no known exploitation of CVE-2022-23649 in the wild and no public exploit code.
Other vulnerabilities in sigstore cosign
- CVE-2022-35929 False positive signature verification in cosign
- CVE-2026-22703 Cosign verification accepts any valid Rekor entry under certain conditions
- CVE-2022-36056 Vulnerabilities with blob verification in sigstore cosign
- CVE-2026-39395 Cosign's verify-blob-attestation reports false positive when payload parsing fails
- CVE-2024-29902 Cosign vulnerable to system-wide denial of service via malicious attachments
Sources
Also known as BIT-cosign-2022-23649, CLEANSTART-2026-QF47090, GHSA-ccxc-vr6p-4858, GO-2022-0326, openSUSE-SU-2024:11860-1.