CVE-2015-8833 in pidgin-otr
Summary
by MITRE
Use-after-free vulnerability in the create_smp_dialog function in gtk-dialog.c in the Off-the-Record Messaging (OTR) pidgin-otr plugin before 4.0.2 for Pidgin allows remote attackers to execute arbitrary code via vectors related to the "Authenticate buddy" menu item.
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Analysis
by VulDB Data Team • 11/07/2024
The CVE-2015-8833 vulnerability represents a critical use-after-free flaw in the Off-the-Record Messaging plugin for Pidgin messaging client. This vulnerability specifically affects the create_smp_dialog function within the gtk-dialog.c file and exists in versions prior to 4.0.2 of the pidgin-otr plugin. The flaw occurs when processing the "Authenticate buddy" menu item, which is a core feature of the OTR protocol designed to verify the identity of communication partners through secure message protocol authentication.
The technical nature of this vulnerability stems from improper memory management within the plugin's graphical user interface components. When a user selects the "Authenticate buddy" option, the create_smp_dialog function creates a dialog window to facilitate the secure messaging protocol authentication process. However, the function fails to properly handle memory deallocation, creating a scenario where freed memory blocks are accessed after being released. This use-after-free condition allows attackers to manipulate the memory state and potentially execute arbitrary code with the privileges of the affected Pidgin process.
The operational impact of this vulnerability is significant as it provides remote attackers with a pathway to compromise systems running vulnerable versions of Pidgin with the OTR plugin. Attackers can exploit this vulnerability by crafting malicious messages or initiating authentication requests that trigger the vulnerable code path. The attack vector is particularly concerning because it leverages legitimate user interactions with the messaging interface, making detection more difficult and increasing the likelihood of successful exploitation. This vulnerability directly aligns with CWE-416, which classifies use-after-free conditions as a serious memory safety issue that can lead to arbitrary code execution.
The security implications extend beyond simple code execution, as this vulnerability can be exploited in the context of a man-in-the-middle attack against secure messaging communications. When successfully exploited, attackers could gain control over the messaging client, potentially intercepting or modifying encrypted communications, impersonating users, or establishing persistent backdoors. The vulnerability affects the integrity and confidentiality of OTR communications, which are specifically designed to provide strong security guarantees for private messaging.
Mitigation strategies for this vulnerability require immediate patching of the pidgin-otr plugin to version 4.0.2 or later, which contains the necessary memory management fixes. System administrators should also implement network monitoring to detect unusual authentication requests and consider implementing additional security measures such as restricting access to the OTR plugin in enterprise environments. The vulnerability demonstrates the importance of proper memory management in GUI applications and highlights the need for regular security updates in third-party plugins that extend core messaging functionality. This issue also aligns with ATT&CK technique T1059.007, which covers the execution of malicious code through legitimate system processes, emphasizing the need for comprehensive endpoint security measures that monitor both system and application behavior.