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EUVD-2025-23815 · Published Jun 10, 2025
CIRCL-Fourq: Missing and wrong validation can lead to incorrect results
Impact
The CIRCL implementation of FourQ fails to validate user-supplied low-order points during Diffie-Hellman key exchange, potentially allowing attackers to force the identity point and compromise session security.
Moreover, there is an incorrect point validation in ScalarMult can lead to incorrect results in the isEqual function and if a point is on the curve.
Patches
Version 1.6.1 (https://github.com/cloudflare/circl/tree/v1.6.1) mitigates the identified issues.
We acknowledge Alon Livne (Botanica Software Labs) for the reported findings.
Technologies
Cloudflare Circl
Weaknesses
CWE-1287CWE-20CWE-347
CVSS scores
- v3.13.7
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
MITRE ATT&CK
InferredWhere this vulnerability fits in an attack
Initial Access
References
- https://access.redhat.com/security/cve/CVE-2025-8556
- https://bugzilla.redhat.com/show_bug.cgi?id=2371624
- https://github.com/cloudflare/circl
- https://github.com/cloudflare/circl/security/advisories/GHSA-2x5j-vhc8-9cwm
- https://github.com/cloudflare/circl/tree/v1.6.1
- https://news.ycombinator.com/item?id=45669593
Potentially impacted assets
See if this affects your attack surface
