CVE-2016-2372 in Pidgin
Summary
by MITRE
An information leak exists in the handling of the MXIT protocol in Pidgin. Specially crafted MXIT data sent via the server could potentially result in an out-of-bounds read. A malicious user, server, or man-in-the-middle attacker can send an invalid size for a file transfer which will trigger an out-of-bounds read vulnerability. This could result in a denial of service or copy data from memory to the file, resulting in an information leak if the file is sent to another user.
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Analysis
by VulDB Data Team • 04/20/2025
The vulnerability identified as CVE-2016-2372 represents a critical information disclosure flaw within Pidgin's implementation of the MXIT protocol, which is a proprietary instant messaging protocol used by the MXit messaging service. This vulnerability specifically affects the file transfer functionality of the client, creating a dangerous condition where improperly formatted data can trigger unexpected behavior in the application's memory management systems. The MXIT protocol implementation in Pidgin serves as a bridge for users to communicate with MXit servers, making it a potential attack vector for malicious actors seeking to exploit weaknesses in the communication stack. The vulnerability manifests when the client receives specially crafted MXIT data that contains invalid file transfer size parameters, which are then processed without adequate validation checks.
The technical exploitation of this vulnerability occurs through an out-of-bounds read condition that arises from insufficient input validation during the processing of MXIT protocol messages. When a malicious entity sends a file transfer request with an invalid size parameter, the Pidgin client attempts to parse this data and allocate memory resources accordingly. However, due to the lack of proper boundary checks, the application reads memory locations beyond the intended buffer boundaries, potentially accessing sensitive data from adjacent memory regions. This type of vulnerability falls under the CWE-125 weakness category, which specifically addresses out-of-bounds read conditions that can lead to information disclosure and system instability. The flaw demonstrates poor memory management practices and inadequate defensive programming techniques that are commonly associated with buffer overflow vulnerabilities, even though the specific mechanism here involves reading rather than writing operations.
The operational impact of CVE-2016-2372 extends beyond simple denial of service scenarios, presenting significant security risks to users of the affected Pidgin client. When exploited, this vulnerability can result in information leakage that exposes sensitive data such as session tokens, user credentials, or other confidential information stored in memory. The attack can be executed by a malicious user, compromised server, or man-in-the-middle attacker who has the capability to intercept and modify network traffic between the client and the MXit server. This information leak could potentially compromise user privacy and enable further attacks, as attackers might gain access to authentication tokens or other sensitive data that could be used to impersonate users or escalate privileges within the messaging system. The vulnerability is particularly concerning because it operates at the protocol level, making it difficult to detect through standard network monitoring tools and potentially allowing attackers to remain undetected while harvesting sensitive information.
Mitigation strategies for this vulnerability should focus on implementing proper input validation and boundary checking mechanisms within the MXIT protocol handler. The recommended approach involves adding comprehensive validation checks for file transfer size parameters and other critical data fields before processing, ensuring that all incoming data conforms to expected ranges and formats. System administrators and users should immediately apply security patches released by the Pidgin development team, which typically include enhanced input sanitization and memory access controls. Additionally, network administrators should consider implementing traffic filtering rules that can detect and block suspicious MXIT protocol traffic patterns. The implementation of defensive programming practices, including the use of modern memory safety techniques and automated testing for boundary conditions, can help prevent similar vulnerabilities from occurring in the future. Organizations should also consider disabling the MXIT protocol support in Pidgin if it is not essential for their operations, as this provides an additional layer of protection against potential exploitation attempts.