CVE-2014-3695 in Pidgin
Summary
by MITRE
markup.c in the MXit protocol plugin in libpurple in Pidgin before 2.10.10 allows remote servers to cause a denial of service (application crash) via a large length value in an emoticon response.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 02/23/2022
The vulnerability identified as CVE-2014-3695 represents a critical denial of service flaw within the MXit protocol plugin of Pidgin messaging client. This issue specifically affects versions prior to 2.10.10 and stems from improper input validation in the markup.c file which handles emoticon processing within the MXit protocol implementation. The vulnerability manifests when remote servers send malformed emoticon responses containing excessively large length values that the application fails to properly handle during parsing operations.
The technical flaw exploits a buffer handling weakness where the application does not adequately validate the length parameter associated with emoticon data received from remote servers. When processing these malformed responses, the application attempts to allocate memory or process data structures based on the malicious length values, leading to memory corruption and subsequent application crash. This represents a classic buffer overflow scenario where the system's memory management routines fail to account for malformed input data that exceeds expected boundaries. The vulnerability operates at the protocol parsing layer within libpurple's plugin architecture, making it particularly dangerous as it can be triggered by external entities without requiring local system compromise.
The operational impact of this vulnerability extends beyond simple service disruption as it can be leveraged by malicious actors to repeatedly crash Pidgin clients used by victims. This denial of service condition affects users of the MXit protocol specifically, though the broader implications suggest potential for similar vulnerabilities in other protocol plugins within the same framework. The attack vector requires only that a remote server send a specially crafted emoticon response, making it particularly dangerous in environments where users may unknowingly interact with malicious servers or where automated attacks can be orchestrated. The vulnerability aligns with CWE-129, which addresses improper validation of length values in buffer operations, and demonstrates how insufficient input validation can lead to application instability.
Mitigation strategies for this vulnerability require immediate patching of affected Pidgin installations to version 2.10.10 or later where the issue has been resolved through proper input validation mechanisms. System administrators should implement network-level filtering to monitor and restrict emoticon data exchanges when possible, though this approach provides only partial protection. The fix implemented in the patched versions involves enhanced validation of length parameters within the emoticon processing routines, ensuring that all input values are properly bounded before memory allocation occurs. Organizations should also consider implementing monitoring solutions to detect unusual patterns of application crashes that might indicate exploitation attempts. This vulnerability underscores the importance of robust input validation practices in messaging applications and aligns with ATT&CK technique T1499.004 for network denial of service attacks, demonstrating how protocol-level flaws can be exploited to disrupt communication services and compromise user experience.