Copyright © 2012 Red Hat, Inc. All rights reserved. Important 2026-07-05T01:30:12 Crypt::DSA: Crypt::DSA: Private key recovery due to biased random number generation 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N CWE-338

Crypt::DSA versions before 1.22 for Perl draw the DSA signing nonce and private key from a biased random generator, leading to private-key recovery. "Crypt::DSA::Util::makerandom forces the high bit of every value it returns to obtain an exactly N-bit integer for prime search. The signing nonce and the private key are drawn from makerandom. Because the high bit is always set, the result is not uniform: its top bit is fixed, producing insecure values." An attacker who collects a modest number of signatures under an affected key, together with the public key, can recover the private key with a lattice attack. Keys used to sign with an affected version should be considered compromised and new keys should be generated.

A flaw was found in Crypt::DSA. Versions before 1.22 for Perl use a biased random number generator when creating the Digital Signature Algorithm (DSA) signing nonce and private key. This bias allows a remote attacker to recover the private key through a lattice attack if they collect a sufficient number of signatures and have access to the public key. This vulnerability compromises the confidentiality of the private key.

A flaw was found in the Perl Crypt::DSA module. The random number generator used for DSA signing nonces and private key generation has a bias (the high bit is always set), allowing an attacker who collects a modest number of signatures to recover the private key via a lattice attack. Red Hat does not ship perl-Crypt-DSA in any supported product. This issue only affects the perl-Crypt-DSA package available in Fedora and EPEL community repositories. Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability. https://www.cve.org/CVERecord?id=CVE-2026-14570 https://nvd.nist.gov/vuln/detail/CVE-2026-14570 https://metacpan.org/release/TIMLEGGE/Crypt-DSA-1.21/source/lib/Crypt/DSA/Util.pm#L56 https://metacpan.org/release/TIMLEGGE/Crypt-DSA-1.22/changes https://metacpan.org/release/TIMLEGGE/Crypt-DSA-1.22/diff/TIMLEGGE/Crypt-DSA-1.21#lib/Crypt/DSA/Util.pm