CVE-2013-6490 in Pidgin
Summary
by MITRE
The SIMPLE protocol functionality in Pidgin before 2.10.8 allows remote attackers to have an unspecified impact via a negative Content-Length header, which triggers a buffer overflow.
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Analysis
by VulDB Data Team • 06/08/2021
The vulnerability identified as CVE-2013-6490 represents a critical buffer overflow flaw within the SIMPLE protocol implementation of Pidgin messaging client versions prior to 2.10.8. This issue arises from insufficient input validation when processing the Content-Length header in SIMPLE protocol messages, creating a potential attack vector that could be exploited by remote adversaries to execute arbitrary code or cause denial of service conditions. The SIMPLE protocol, which is used for instant messaging and presence information, serves as a communication framework that enables users to exchange messages and status updates across different messaging systems.
The technical flaw manifests when the Pidgin client receives a malformed Content-Length header value that is negative in nature. This negative value, when processed without proper validation, causes the application to allocate insufficient memory buffers or perform invalid memory operations during message parsing. The buffer overflow occurs because the application does not properly validate that the Content-Length header contains a positive integer value before using it to determine buffer allocation sizes or memory access boundaries. This type of vulnerability falls under the CWE-121 category of stack-based buffer overflow, where the improper handling of input data leads to memory corruption that can be exploited to overwrite adjacent memory locations.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it provides attackers with the potential to execute arbitrary code on vulnerable systems. When a malicious actor sends a specially crafted SIMPLE protocol message containing a negative Content-Length header, the vulnerable Pidgin client may crash or, in more sophisticated exploitation attempts, allow remote code execution. This poses significant risks to users who rely on Pidgin for communication, as the attack can be initiated remotely without requiring authentication or physical access to the target system. The vulnerability affects the core messaging functionality of the application, potentially compromising user privacy and system integrity.
Mitigation strategies for CVE-2013-6490 primarily involve upgrading to Pidgin version 2.10.8 or later, which includes proper input validation for Content-Length headers within the SIMPLE protocol implementation. Additionally, network administrators should consider implementing defensive measures such as filtering or blocking SIMPLE protocol traffic at network boundaries when the protocol is not required for business operations. The vulnerability demonstrates the importance of proper input validation and memory management in client-side applications, aligning with ATT&CK technique T1203 which covers exploitation for client execution through protocol manipulation. Organizations should also implement regular security patch management processes to ensure timely remediation of similar vulnerabilities in other messaging applications and protocols.