CVE-2024-29902
Vulnérabilité moyenne dans cosign (sigstore)
Description
Cosign provides code signing and transparency for containers and binaries. Prior to version 2.2.4, a remote image with a malicious attachment can cause denial of service of the host machine running Cosign. This can impact other services on the machine that rely on having memory available such as a Redis database which can result in data loss. It can also impact the availability of other services on the machine that will not be available for the duration of the machine denial. The root cause of this issue is that Cosign reads the attachment from a remote image entirely into memory without checking the size of the attachment first. As such, a large attachment can make Cosign read a large attachment into memory; If the attachments size is larger than the machine has memory available, the machine will be denied of service. The Go runtime will make a SigKill after a few seconds of system-wide denial. This issue can allow a supply-chain escalation from a compromised registry to the Cosign user: If an attacher has compromised a registry or the account of an image vendor, they can include a malicious attachment and hurt the image consumer. Version 2.2.4 contains a patch for the vulnerability.
Gravité et risque d'exploitation
CVE-2024-29902 obtient un score CVSS de 4.2/10, soit une gravité moyenne. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.66 %, ce qui la place devant 50.6 % des CVE référencées.
Que faire ?
- Vérifiez si cosign (versions < 2.2.4) est présent sur votre parc.
- Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
- À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
- Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.
Références
- https://github.com/sigstore/cosign/security/advisories/GHSA-88jx-383q-w4qc
- https://github.com/sigstore/cosign/commit/629f5f8fa672973503edde75f84dcd984637629e
- https://github.com/google/go-containerregistry/blob/a0658aa1d0cc7a7f1bcc4a3af9155335b6943f40/pkg/v1/remote/layer.go#L36-L40
- https://github.com/sigstore/cosign/blob/9bc3ee309bf35d2f6e17f5d23f231a3d8bf580bc/pkg/oci/remote/remote.go#L228-L239
- https://github.com/sigstore/cosign/releases/tag/v2.2.4