Forged-signature trust via unauthenticated Rekor public keys
Published Nov 10, 2023 · Updated Sep 3, 2024
Improper signature verification in Sigstore Gitsign 0.6.0 through releases before 0.8.0 allows attackers to make forged signatures appear trusted. The rekorPubsFromClient function in pkg/rekor/rekor.go fetched a key payload from the configured Rekor API and added it as an active transparency-log key without TUF authentication. Exploitation requires control of that Rekor server and user interaction during verification; no compromise of the default public instance was known.
Summary
What happened
Improper signature verification in Sigstore Gitsign 0.6.0 through releases before 0.8.0 allows attackers to make forged signatures appear trusted. The rekorPubsFromClient function in pkg/rekor/rekor.go fetched a key payload from the configured Rekor API and added it as an active transparency-log key without TUF authentication. Exploitation requires control of that Rekor server and user interaction during verification; no compromise of the default public instance was known.
The record
- CVE
- CVE-2023-47122
- Published
- Nov 10, 2023
- Updated
- Sep 3, 2024
- Vendor
- Sigstore
- Product
- Gitsign
- Classifications
- CWE-347, T1553.006
- Attack vector
- network
- Privileges
- admin
Timeline
How it unfolded
- Nov 10, 2023CVE publishedPublication date reported by the CVE source.
- Sep 3, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 0.6.0, < 0.8.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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