CVE-2016-2375 in Pidgin
Summary
by MITRE
An exploitable out-of-bounds read exists in the handling of the MXIT protocol in Pidgin. Specially crafted MXIT contact information sent from the server can result in memory disclosure.
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Analysis
by VulDB Data Team • 04/20/2025
The vulnerability identified as CVE-2016-2375 represents a critical out-of-bounds read flaw within Pidgin's MXIT protocol implementation, exposing the messaging client to potential exploitation through maliciously crafted server responses. This vulnerability resides in the client-side processing logic that handles incoming MXIT contact information, where insufficient input validation and boundary checking allows attackers to manipulate memory access patterns. The MXIT protocol, used for instant messaging and presence information exchange, becomes a vector for memory disclosure when servers send specially crafted contact data that exceeds expected buffer boundaries. This flaw specifically impacts Pidgin versions prior to 2.11.0, making it particularly concerning given the widespread adoption of this messaging client across various operating systems and network environments.
The technical nature of this vulnerability stems from improper input validation mechanisms within the MXIT protocol handler, which fails to properly validate the length and structure of incoming contact information before processing. When the client receives malformed MXIT data containing oversized contact entries or malformed data structures, the memory management routines attempt to read beyond allocated buffer boundaries, resulting in information disclosure. This memory disclosure can potentially expose sensitive data from the application's memory space including stack contents, heap data, or other process memory segments that may contain authentication tokens, session information, or other confidential data. The vulnerability is classified under CWE-125 as an out-of-bounds read, representing a fundamental memory safety issue that can lead to further exploitation techniques including information leakage, denial of service, or potentially remote code execution depending on the specific memory contents accessed.
The operational impact of CVE-2016-2375 extends beyond simple information disclosure, as the memory disclosure can provide attackers with insights into the application's memory layout and internal state. This information can be leveraged to facilitate more sophisticated attacks by enabling attackers to bypass security mechanisms, predict memory locations, or craft more targeted exploitation payloads. The vulnerability is particularly dangerous in enterprise environments where Pidgin is used for business communications, as it could potentially expose sensitive corporate data or communication patterns. Network administrators and security teams must consider the risk of this vulnerability being exploited in conjunction with other attacks, as the leaked memory information can aid in developing more effective exploitation strategies. The issue affects all platforms where Pidgin is deployed, including Windows, macOS, and various Linux distributions, making it a widespread concern for organizations maintaining secure communication infrastructure.
Mitigation strategies for CVE-2016-2375 primarily focus on updating Pidgin to version 2.11.0 or later, which includes patches that properly validate MXIT protocol input and implement robust boundary checking mechanisms. System administrators should prioritize patch deployment across all affected systems, particularly in environments where Pidgin is used for sensitive communications. Additional defensive measures include implementing network-level filtering to restrict MXIT protocol traffic from untrusted sources, enabling application whitelisting policies that restrict Pidgin execution to authorized users, and monitoring for unusual network traffic patterns that might indicate exploitation attempts. Organizations should also consider disabling MXIT protocol support entirely if it is not required for business operations, as this eliminates the attack surface associated with this vulnerability. The mitigation approach aligns with ATT&CK technique T1071.004 for application layer protocol manipulation and T1068 for exploit development, emphasizing the need for both defensive and proactive security measures to protect against exploitation of memory safety vulnerabilities.