What’s Vulnerable › Vulnerabilities

CVE-2022-24884: Trivial signature forgery in ecdsautils

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.0% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2022-05-06 · updated 2026-06-17
• Weakness: CWE-347

Description

ecdsautils is a tiny collection of programs used for ECDSA (keygen, sign, verify). `ecdsa_verify_[prepare_]legacy()` does not check whether the signature values `r` and `s` are non-zero. A signature consisting only of zeroes is always considered valid, making it trivial to forge signatures. Requiring multiple signatures from different public keys does not mitigate the issue: `ecdsa_verify_list_legacy()` will accept an arbitrary number of such forged signatures. Both the `ecdsautil verify` CLI command and the libecdsautil library are affected. The issue has been fixed in ecdsautils 0.4.1. All older versions of ecdsautils (including versions before the split into a library and a CLI utility) are vulnerable.

Affected products

• Debian Linux: 9.0, 10.0, 11.0
• Ecdsautils Project Ecdsautils: before 0.4.1 — fixed in 0.4.1
• Fedoraproject Fedora: 34, 35, 36

How to fix

Upgrade to a fixed version: Ecdsautils Project Ecdsautils 0.4.1. Check the vendor advisory for mitigations.

References

• https://github.com/freifunk-gluon/ecdsautils/commit/1d4b091abdf15ad7b2312535b5b95ad70f6dbd08
• https://github.com/freifunk-gluon/ecdsautils/commit/39b6d0a77414fd41614953a0e185c4eefa2f88ad
• https://github.com/freifunk-gluon/ecdsautils/security/advisories/GHSA-qhcg-9ffp-78pw
• https://lists.debian.org/debian-lts-announce/2022/05/msg00007.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4AKQH5WCBMJA3ODCSNERY6HVX4BX3ITG/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/G2JT57AAFIEL7JDO2ZBV25JKYME5NU54/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L7UBR3M4U3LA46BHXYSH7EN5GDG44GK7/
• https://www.debian.org/security/2022/dsa-5132
• https://github.com/freifunk-gluon/ecdsautils/commit/1d4b091abdf15ad7b2312535b5b95ad70f6dbd08
• https://github.com/freifunk-gluon/ecdsautils/commit/39b6d0a77414fd41614953a0e185c4eefa2f88ad
• https://github.com/freifunk-gluon/ecdsautils/security/advisories/GHSA-qhcg-9ffp-78pw
• https://lists.debian.org/debian-lts-announce/2022/05/msg00007.html

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