Description
HTTP::Session2 versions before 1.12 for Perl for Perl may generate weak session ids using the rand() function. The HTTP::Session2 session id generator returns a SHA-1 hash seeded with the built-in rand function, the epoch time, and the PID. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand() function is unsuitable for cryptographic usage. HTTP::Session2 after version 1.02 will attempt to use the /dev/urandom device to generate a session id, but if the device is unavailable (for example, under Windows), then it will revert to the insecure method described above.
Problem types
CWE-340 Generation of Predictable Numbers or Identifiers
CWE-338 Use of Cryptographically Weak Pseudo-Random Number Generator
Product status
Any version before 1.12
Timeline
| 2014-07-31: | version 1.02 HTTP::Session2 released that attempts to use /dev/urandom. |
| 2026-02-24: | version 1.11 HTTP::Session2 deprecated |
| 2026-02-26: | version 1.12 HTTP::Session2 released with a fix with a portable solution. |
References
www.openwall.com/lists/oss-security/2026/02/27/12
metacpan.org/...ion2-1.11/source/lib/HTTP/Session2/Random.pm
metacpan.org/...1.01/source/lib/HTTP/Session2/ServerStore.pm
metacpan.org/release/TOKUHIROM/HTTP-Session2-1.12/changes
github.com/...9cfde4d7e0965172aef5dcfa3b03bb48df93e636.patch