/ 
CGI-Session-4.11 UNAUTHORIZED RELEASE
/ CGI::Session::Serialize::yaml
Security Advisories (2)
CPANSA-CGI-Session-2006-01 (2006-04-06)

possible SQL injection attack

CVE-2026-56016 (2026-07-01)

CGI::Session::ID::md5 versions before 4.49 for Perl generate predictable session ids from low-entropy sources. The generate_id method builds the session id from a MD5 digest of the process id, the epoch time, and the built-in rand() function. All three are predictable, low-entropy sources: the PID is drawn from a small range, the epoch time can be guessed or read from the HTTP Date header, and Perl's rand() is unsuitable for security purposes because it is predictable and reversible. An attacker who predicts a session id can impersonate the corresponding session and bypass authentication.

NAME

CGI::Session::Serialize::yaml - serializer for CGI::Session

DESCRIPTION

This library can be used by CGI::Session to serialize session data. It uses YAML, or the faster C implementation, YAML::Syck if it is available. YAML serializers exist not just for Perl but also other dynamic languages, such as PHP, Python, and Ruby, so storing session data in this format makes it easy to share session data across different languages.

YAML is made to be friendly for humans to parse as well as other computer languages. It creates a format that is easier to read than the default serializer.

METHODS

freeze($class, \%hash)

Receives two arguments. First is the class name, the second is the data to be serialized. Should return serialized string on success, undef on failure. Error message should be set using set_error()|CGI::Session::ErrorHandler/"set_error()"

thaw($class, $string)

Received two arguments. First is the class name, second is the YAML data string. Should return thawed data structure on success, undef on failure. Error message should be set using set_error()|CGI::Session::ErrorHandler/"set_error()"

SEE ALSO

CGI::Session, YAML, YAML::Syck.