CVE-2016-2564 in Community Suite
Summary
by MITRE
Invision Power Services (IPS) Community Suite before 4.1.9 makes session hijack easier by relying on the PHP uniqid function without the more_entropy flag. Attackers can guess an Invision Power Board session cookie if they can predict the exact time of cookie generation.
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Analysis
by VulDB Data Team • 09/19/2020
The vulnerability identified as CVE-2016-2564 affects Invision Power Services (IPS) Community Suite versions prior to 4.1.9, representing a significant session management weakness that directly impacts application security. This flaw resides in the session cookie generation mechanism where the software relies on PHP's uniqid function without utilizing the more_entropy flag, creating predictable session identifiers that can be exploited by malicious actors. The vulnerability specifically targets the randomness and uniqueness properties of session tokens, which are fundamental to maintaining user authentication integrity within web applications.
The technical root cause of this vulnerability stems from the predictable nature of PHP's uniqid function when called without the more_entropy parameter. When this flag is omitted, uniqid generates identifiers based primarily on the current timestamp, making it susceptible to time-based prediction attacks. In the context of IPS Community Suite, this means that an attacker who can determine or estimate the precise time when a session cookie was generated can potentially compute valid session identifiers for other users. This weakness directly violates security principles outlined in CWE-330, which addresses the use of insufficiently random values in security contexts. The vulnerability creates a direct pathway for session hijacking attacks where unauthorized parties can assume legitimate user identities and gain access to protected resources within the community platform.
The operational impact of this vulnerability extends beyond simple session theft, as it enables attackers to perform unauthorized actions within the IPS Community Suite environment. Successful exploitation allows threat actors to access user accounts, view private content, post messages, modify settings, and potentially escalate privileges within the application. The attack surface is particularly concerning for community platforms where users may have varying levels of access and sensitive information is shared. This vulnerability aligns with ATT&CK technique T1563.002, which covers "Access Token Manipulation" through session hijacking, and represents a critical weakness in the application's authentication and session management controls. Organizations using vulnerable versions of IPS Community Suite face significant risks including data breaches, unauthorized content modification, and potential compromise of user credentials and personal information.
Mitigation strategies for CVE-2016-2564 require immediate implementation of the official patch released by Invision Power Services for versions 4.1.9 and later. The recommended solution involves updating the session cookie generation process to utilize PHP's uniqid function with the more_entropy flag enabled, ensuring that session identifiers incorporate sufficient randomness to prevent prediction attacks. Security teams should also implement additional protective measures including session regeneration after login events, proper session timeout configurations, and monitoring for suspicious authentication patterns. Network-level protections such as secure cookie flags, HttpOnly attributes, and proper session management practices should complement the core patch. Organizations must conduct thorough vulnerability assessments to identify any other applications or systems that might be using similar vulnerable implementations of session generation mechanisms. The remediation process should also include user education regarding session security and the importance of logging out of community platforms, particularly on shared or public computing devices.