CPANSA-Crypt-DSA-2026-14570: Crypt-DSA vulnerability

Publisher giterlizzi Document category csaf_security_advisory
Initial release date 2026-07-05T00:00:00 Engine CSAF Perl Toolkit 0.26
Current release date 2026-07-05T00:00:00 Build Date
Current version 1 Status final
CVSS v3.1 Base Score 7.5 Severity
Original language Language en
Also referred to

Vulnerability Description

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.

Vulnerabilities

CVE-2026-14570

Vulnerability Description

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.

Weakness CWE-330 : Use of Insufficiently Random Values

Product status

Known affected
Product Score
Crypt-DSA less than 1.22
CVSS Version CVSS Vector CVSS Base Score CVSS Base Severity
3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N 7.5 High
Fixed

giterlizzi

Namespace: https://github.com/giterlizzi/

gdt@cpan.org

References

Revision history

Version Date of the revision Summary of the revision
1 Sun Jul 5 00:00:00 2026 First release

Sharing rules

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