{"id":86988,"date":"2026-04-25T07:07:05","date_gmt":"2026-04-25T07:07:05","guid":{"rendered":""},"modified":"-0001-11-30T00:00:00","modified_gmt":"-0001-11-30T00:00:00","slug":"cve-2025-40933-predictable-session-id-generation-in-apache-authany-cookie","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-40933-predictable-session-id-generation-in-apache-authany-cookie\/","title":{"rendered":"CVE-2025-40933: Predictable Session ID Generation in Apache::AuthAny::Cookie<\/strong>"},"content":{"rendered":"

Overview<\/strong><\/p>\n

This report covers a critical vulnerability in the Apache::AuthAny::Cookie module for Perl. The flaw lies in the insecure generation of session ids, which could be leveraged by an attacker to gain unauthorized access to systems. Anyone using version 0.201 or earlier of this module is vulnerable, and due to the potential for system compromise or data leakage, it is crucial that this issue is addressed promptly.<\/p>\n

Vulnerability Summary<\/strong><\/p>\n

CVE ID: CVE-2025-40933
\nSeverity: High (7.5)
\nAttack Vector: Network
\nPrivileges Required: None
\nUser Interaction: None
\nImpact: System compromise or data leakage<\/p>\n

Affected Products<\/strong><\/p>\n

Product | Affected Versions<\/p>\n

Apache::AuthAny::Cookie for Perl | 0.201 or earlier<\/p>\n

How the Exploit Works<\/strong><\/p>\n

An attacker can exploit this vulnerability by predicting the session ids generated by the module. The module generates these ids using an MD5 hash of the epoch time and a call to the built-in rand function. The epoch time may be guessed, especially if leaked from the HTTP Date header. The built-in rand function is not cryptographically secure, making this process even more vulnerable. Predictable session ids could allow an attacker to hijack sessions and gain unauthorized access to the system.<\/p>\n

Conceptual Example Code<\/strong><\/p>\n

The following pseudocode illustrates how an attacker might predict a session id:<\/p>\n

import time\nimport hashlib\n# Guess the epoch time\nepoch_time = int(time.time())\n# Guess the value from the rand function\nrand_val = 12345  # This value is usually not secure\n# Generate the session id\nsession_id = hashlib.md5(str(epoch_time) + str(rand_val)).hexdigest()\nprint(\"Predicted session id: \" + session_id)<\/code><\/pre>\n
In the actual attack, the attacker would use this predicted session id to impersonate a valid user in the system.<\/p>\n
Mitigation<\/strong><\/p>\n
To mitigate this vulnerability, it is recommended to apply the patch provided by the vendor. In the absence of a patch, a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can be used as a temporary mitigation measure. However, these options do not address the root cause of the vulnerability and should be considered short-term solutions.<\/p>\n","protected":false},"excerpt":{"rendered":"
Overview This report covers a critical vulnerability in the Apache::AuthAny::Cookie module for Perl. The flaw lies in the insecure generation of session ids, which could be leveraged by an attacker to gain unauthorized access to systems. Anyone using version 0.201 or earlier of this module is vulnerable, and due to the potential for system compromise […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"footnotes":""},"categories":[],"tags":[],"vendor":[],"product":[],"attack_vector":[],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-86988","post","type-post","status-publish","format-standard","hentry"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t