Description
CryptX versions before 0.088 for Perl do not reseed the Crypt::PK PRNG state after forking. The Crypt::PK::RSA, Crypt::PK::DSA, Crypt::PK::DH, Crypt::PK::ECC, Crypt::PK::Ed25519 and Crypt::PK::X25519 modules seed a per-object PRNG state in their constructors and reuse it without fork detection. A Crypt::PK::* object created before `fork()` shares byte-identical PRNG state with every child process, and any randomized operation they perform can produce identical output, including key generation. Two ECDSA or DSA signatures from different processes are enough to recover the signing private key through nonce-reuse key recovery. This affects preforking services such as the Starman web server, where a Crypt::PK::* object loaded at startup is inherited by every worker process.
Problem types
CWE-335 Incorrect Usage of Seeds in Pseudo-Random Number Generator (PRNG)
CWE-338 Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
Product status
Any version before 0.088
Timeline
| 2026-04-18: | Issue discovered. |
| 2026-04-21: | Reported to upstream maintainer. |
| 2026-04-23: | CryptX 0.088 released with fix. |
References
www.openwall.com/lists/oss-security/2026/04/23/2
github.com/...CryptX/security/advisories/GHSA-24c2-gp6c-24c6
github.com/...CryptX/security/advisories/GHSA-24c2-gp6c-24c6
github.com/...9a1dd3e0c27d68e32450be5538b864c2b115ee15.patch
metacpan.org/release/MIK/CryptX-0.088