CVE-2013-6481 in Pidgin
Summary
by MITRE
libpurple/protocols/yahoo/libymsg.c in Pidgin before 2.10.8 allows remote attackers to cause a denial of service (crash) via a Yahoo! P2P message with a crafted length field, which triggers a buffer over-read.
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Analysis
by VulDB Data Team • 06/08/2021
The vulnerability identified as CVE-2013-6481 affects Pidgin messaging client versions prior to 2.10.8 and specifically targets the libpurple library's Yahoo messenger protocol communication including peer-to-peer messaging functionality. The flaw represents a classic buffer over-read condition that occurs when processing malformed P2P messages from remote Yahoo! users, making it particularly dangerous in networked environments where users may receive unsolicited communications.
The technical root cause of this vulnerability stems from insufficient input validation within the Yahoo! P2P message processing code. When a maliciously crafted message arrives with an improperly sized length field, the application fails to properly bounds-check the buffer before reading data from memory locations beyond the allocated buffer boundaries. This buffer over-read condition leads to memory corruption and ultimately results in application crash or termination. According to CWE classification, this vulnerability maps to CWE-125: "Out-of-bounds Read" which is categorized under the broader weakness of buffer overflow conditions that can lead to system instability and potential code execution.
The operational impact of this vulnerability extends beyond simple denial of service as it creates an attack vector that can be exploited by remote adversaries without requiring authentication or privileged access. An attacker can simply send a specially crafted Yahoo! P2P message to any victim running an affected Pidgin version to trigger the crash. This makes the vulnerability particularly dangerous in environments where users may receive messages from unknown or untrusted sources, such as public chat rooms, social media platforms, or corporate messaging systems where Pidgin is deployed. The vulnerability can be leveraged in distributed denial of service scenarios where multiple targets are simultaneously attacked, or as part of broader reconnaissance efforts to identify vulnerable systems within a network.
From a cybersecurity perspective, this vulnerability aligns with ATT&CK technique T1499.002: "Endpoint Denial of Service" and demonstrates how seemingly innocuous messaging protocols can become attack vectors. The vulnerability affects the availability aspect of the CIA triad by compromising system stability and user access to communication services. Organizations using Pidgin for corporate communications should consider this vulnerability as part of their broader security posture assessment, particularly in environments where message filtering or user access controls are minimal. The remediation strategy involves immediate patching of Pidgin to version 2.10.8 or later, which includes proper bounds checking and input validation for the Yahoo! P2P message handling code. Additionally, network administrators should implement message filtering policies and consider deploying network segmentation to limit exposure to untrusted messaging sources while monitoring for suspicious message patterns that could indicate exploitation attempts.