Threats affecting pkg:github/Crypt-DSA

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.

Crypt::DSA versions before 1.21 for Perl contain a vulnerability where the nonce used in digital signatures is reused across multiple signatures. This reuse occurs because the nonce material is cached in the Key object and never cleared, causing identical nonce values in subsequent signatures. As a result, private keys can be recovered if the same key signs more than once. This vulnerability is classified as CWE-323 and has a critical severity with a CVSS score of 9.1.

Crypt::DSA versions through 1.19 for Perl use 2-args open, allowing existing files to be modified.

Crypt::DSA versions before 1.20 for Perl generate seeds using rand. Seeds were generated using Perl's built-in rand function, which is predictable and unsuitable for security usage.