CVE-2016-2365 in Pidgin
Summary
by MITRE
A denial of service vulnerability exists in the handling of the MXIT protocol in Pidgin. Specially crafted MXIT data sent via the server could potentially result in a null pointer dereference. A malicious server or an attacker who intercepts the network traffic can send invalid data to trigger this vulnerability and cause a crash.
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Analysis
by VulDB Data Team • 04/20/2025
The vulnerability identified as CVE-2016-2365 represents a critical denial of service weakness within Pidgin's implementation of the MXIT protocol handling mechanism. This protocol is used for instant messaging and communication services, particularly within the MXIT ecosystem that was popular in certain regions. The flaw manifests specifically during the processing of incoming MXIT protocol data, where the application fails to properly validate or sanitize incoming information before attempting to process it. When malformed or specially crafted MXIT data reaches the client application, it triggers an unexpected execution path that leads to a null pointer dereference condition.
The technical nature of this vulnerability stems from inadequate input validation and error handling within Pidgin's MXIT protocol plugin. When the application receives data that does not conform to expected protocol specifications, the code fails to properly handle these exceptional conditions, resulting in a program crash rather than graceful error recovery. This null pointer dereference occurs because the application attempts to access memory at a null address when processing the malformed MXIT data, causing the entire client application to terminate unexpectedly. The vulnerability is particularly concerning because it can be triggered remotely through network traffic interception or by a malicious server that deliberately sends crafted packets.
From an operational perspective, this vulnerability presents significant risks to users of Pidgin who are connected to MXIT-enabled networks or services. Attackers can exploit this weakness by either intercepting network traffic between the client and server or by compromising a MXIT server to send malicious data directly to connected clients. The impact extends beyond simple service disruption as the crash can occur without any user interaction, potentially affecting multiple users simultaneously if the malicious data is broadcast to a channel or group. This makes the vulnerability particularly dangerous in environments where Pidgin is used for critical communication purposes.
The security implications of CVE-2016-2365 align with CWE-476 which describes null pointer dereference conditions, and the vulnerability can be categorized under the ATT&CK technique T1499.3 for network denial of service attacks. The flaw represents a classic example of insufficient input validation and error handling, where the application does not properly account for malformed data during protocol processing. Organizations using Pidgin for MXIT communications should implement immediate mitigations including updating to patched versions of the software, implementing network monitoring to detect suspicious MXIT traffic patterns, and considering network segmentation to limit the potential impact of such attacks. The vulnerability underscores the importance of robust input validation in network protocol implementations and demonstrates how seemingly minor flaws in protocol handling can result in significant service disruption.