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Fencer Vulns
critical 9.8

CVE-2022-31053 json

Signature forgery in Biscuit

published 2022-06-13 4 y ago modified 2026-06-17 4 mo ago also EUVD-2022-5973 , GHSA-75rw-34q6-72cr , GO-2022-0564 , HSEC-2023-0002

cvss
9.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.0%
EPSS 1.0% chance of exploitation in 30 days, percentile 63%
public exploits
0
none known

Summary

Biscuit is an authentication and authorization token for microservices architectures. The Biscuit specification version 1 contains a vulnerable algorithm that allows malicious actors to forge valid Γ-signatures. Such an attack would allow an attacker to create a token with any access level. The version 2 of the specification mandates a different algorithm than gamma signatures and as such is not affected by this vulnerability. The Biscuit implementations in Rust, Haskell, Go, Java and Javascript all have published versions following the v2 specification. There are no known workarounds for this issue.

Patch / fix

  • crates.io biscuit-auth 2.0.0
  • go github.com/biscuit-auth/biscuit-go 2.0.0
  • maven com.clever-cloud:biscuit-java 2.0.0
  • hackage biscuit-haskell 0.2.0.0
  • biscuitsec biscuit-go 2.0.0
  • clever-cloud biscuit-java 2.0.0

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
total
Assessed
18 mo ago

Exploit prediction

1.03% chance of exploitation in the next 30 days, higher than 63% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/biscuit-auth/biscuit/security/advisories/GHSA-75rw-34q6-72cr referenced PoC, tagged "exploit" by a source, unverified
  • eprint.iacr.org https://eprint.iacr.org/2020/1484 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
GitHub 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P
OSV 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
crates.io biscuit-auth
>=1.0.0, <2.0.0
2.0.0
go github.com/biscuit-auth/biscuit-go
<2.0.0
all versions
2.0.0
maven com.clever-cloud:biscuit-java
<2.0.0
2.0.0
hackage biscuit-haskell
>=0.1.0.0, <0.2.0.0
0.2.0.0

Affected products

  • biscuit-auth biscuit

Classification

Weakness
  • CWE-347 Improper Verification of Cryptographic Signature

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.