CVE-2022-24884: Trivial signature forgery in ecdsautils

First published: Thu May 05 2022(Updated: )

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.

Credit: security-advisories@github.com security-advisories@github.com

Affected Software	Affected Version	How to fix
ubuntu/ecdsautils	<0.3.2+	0.3.2+
ubuntu/ecdsautils	<0.3.2+	0.3.2+
ubuntu/ecdsautils	<0.3.2+	0.3.2+
ubuntu/ecdsautils	<0.4.1-1	0.4.1-1
	<0.4.1
	=34
	=35
	=36
	=9.0
	=10.0
	=11.0
Ecdsautils Project Ecdsautils	<0.4.1
Fedoraproject Fedora	=34
Fedoraproject Fedora	=35
Fedoraproject Fedora	=36
Debian Debian Linux	=9.0
Debian Debian Linux	=10.0
Debian Debian Linux	=11.0
debian/ecdsautils		0.3.2+git20151018-2+deb10u1 0.3.2+git20151018-2+deb11u1 0.4.1-3