/ 
Apache-Session-1.94
/ Apache::Session::Generate::MD5
Security Advisories (3)
CVE-2013-10075 (2026-05-08)

Apache::Session versions through 1.94 for Perl re-creates deleted sessions. The session stores Apache::Session::Store::File and Apache::Session::Store::DB_File will create a session that does not exist. This can lead to sessions being revived, potentially with data that was to be deleted.

CVE-2025-40931 (2026-03-05)

Apache::Session::Generate::MD5 versions through 1.94 for Perl create insecure session id. Apache::Session::Generate::MD5 generates session ids insecurely. The default session id generator returns a MD5 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. Predicable session ids could allow an attacker to gain access to systems. Note that the libapache-session-perl package in some Debian-based Linux distributions may be patched to use Crypt::URandom.

CVE-2026-5081 (2026-05-06)

Apache::Session::Generate::ModUniqueId versions from 1.54 through 1.94 for Perl session ids are insecure. Apache::Session::Generate::ModUniqueId (added in version 1.54) uses the value of the UNIQUE_ID environment variable for the session id. The UNIQUE_ID variable is set by the Apache mod_unique_id plugin, which generates unique ids for the request. The id is based on the IPv4 address, the process id, the epoch time, a 16-bit counter and a thread index, with no obfuscation. The server IP is often available to the public, and if not available, can be guessed from previous session ids being issued. The process ids may also be guessed from previous session ids. The timestamp is easily guessed (and leaked in the HTTP Date response header). The purpose of mod_unique_id is to assign a unique id to requests so that events can be correlated in different logs. The id is not designed, nor is it suitable for security purposes.

NAME

Apache::Session::Generate::MD5 - Use MD5 to create random object IDs

SYNOPSIS

use Apache::Session::Generate::MD5;

$id = Apache::Session::Generate::MD5::generate();

DESCRIPTION

This module fulfills the ID generation interface of Apache::Session. The IDs are generated using a two-round MD5 of a random number, the time since the epoch, the process ID, and the address of an anonymous hash. The resultant ID number is highly entropic on Linux and other platforms that have good random number generators. You are encouraged to investigate the quality of your system's random number generator if you are using the generated ID numbers in a secure environment.

This module can also examine session IDs to ensure that they are, indeed, session ID numbers and not evil attacks. The reader is encouraged to consider the effect of bogus session ID numbers in a system which uses these ID numbers to access disks and databases.

This modules takes one argument in the usual Apache::Session style. The argument is IDLength, and the value, between 0 and 32, tells this module where to truncate the session ID. Without this argument, the session ID will be 32 hexadecimal characters long, equivalent to a 128-bit key.

AUTHOR

This module was written by Jeffrey William Baker <jwbaker@acm.org>.

SEE ALSO

Apache::Session