{"id":"UBUNTU-CVE-2025-40923","details":"Plack-Middleware-Session before version 0.35 for Perl generates session ids insecurely. The default 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. Predicable session ids could allow an attacker to gain access to systems.","modified":"2026-01-20T17:34:25.075349Z","published":"2025-07-16T13:15:00Z","upstream":["CVE-2025-40923"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2025-40923"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2025-40923"},{"type":"REPORT","url":"https://lists.security.metacpan.org/cve-announce/msg/31223483/"},{"type":"REPORT","url":"https://github.com/plack/Plack-Middleware-Session/pull/52"},{"type":"REPORT","url":"https://metacpan.org/release/MIYAGAWA/Plack-Middleware-Session-0.34/source/lib/Plack/Session/State.pm#L22"},{"type":"REPORT","url":"https://security.metacpan.org/docs/guides/random-data-for-security.html"}],"affected":[{"package":{"name":"libplack-middleware-session-perl","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/libplack-middleware-session-perl@0.30-1?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.30-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libplack-middleware-session-perl","binary_version":"0.30-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-40923.json"}},{"package":{"name":"libplack-middleware-session-perl","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/libplack-middleware-session-perl@0.30-2?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.30-1","0.30-2"],"ecosystem_specific":{"binaries":[{"binary_name":"libplack-middleware-session-perl","binary_version":"0.30-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-40923.json"}},{"package":{"name":"libplack-middleware-session-perl","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/libplack-middleware-session-perl@0.33-1?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.32-1","0.33-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libplack-middleware-session-perl","binary_version":"0.33-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-40923.json"}},{"package":{"name":"libplack-middleware-session-perl","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/libplack-middleware-session-perl@0.33-1?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.33-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libplack-middleware-session-perl","binary_version":"0.33-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-40923.json"}},{"package":{"name":"libplack-middleware-session-perl","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/libplack-middleware-session-perl@0.33-2?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.33-2"],"ecosystem_specific":{"binaries":[{"binary_name":"libplack-middleware-session-perl","binary_version":"0.33-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-40923.json"}},{"package":{"name":"libplack-middleware-session-perl","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/libplack-middleware-session-perl@0.36-1?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.34-1","0.36-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libplack-middleware-session-perl","binary_version":"0.36-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-40923.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L"},{"type":"Ubuntu","score":"medium"}]}