CVE-2002-0251 in licq
Summary
by MITRE
Buffer overflow in licq 1.0.4 and earlier allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a long string of format string characters such as "%d".
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Analysis
by VulDB Data Team • 10/22/2024
The vulnerability identified as CVE-2002-0251 represents a critical buffer overflow flaw discovered in the licq instant messaging client version 1.0.4 and earlier. This vulnerability resides within the application's handling of format string arguments, specifically when processing user input containing format specifiers such as "%d". The licq client was widely used for instant messaging across various platforms including linux and unix systems, making this vulnerability particularly concerning for widespread impact. The flaw stems from improper input validation and insufficient bounds checking when processing format strings, creating an exploitable condition that could be leveraged by remote attackers to compromise system integrity.
The technical implementation of this vulnerability exploits the fundamental weakness in how the licq application processes format strings without adequate sanitization measures. When a remote attacker sends a specially crafted message containing an excessively long format string sequence, the application fails to properly validate the input length before attempting to process it through functions that handle format string operations. This lack of proper input boundary checking allows the attacker to overwrite adjacent memory locations in the application's stack, potentially leading to arbitrary code execution or complete application crash. The vulnerability manifests as a classic stack-based buffer overflow condition that can be triggered through network communication, making it particularly dangerous in networked environments where the application receives untrusted input from remote peers.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable remote code execution on affected systems. When exploited successfully, the buffer overflow could allow attackers to inject and execute malicious code within the context of the licq process, potentially leading to full system compromise. The vulnerability affects systems running licq versions 1.0.4 and earlier, which were prevalent during the early 2000s period when instant messaging applications were rapidly gaining adoption. Given that licq was commonly used in enterprise and personal environments, the potential for widespread exploitation was significant, particularly in scenarios where users received messages from untrusted sources. The vulnerability also represents a failure in proper input validation practices that aligns with common weakness patterns identified in the CWE database under CWE-121 for stack-based buffer overflow conditions.
Mitigation strategies for this vulnerability primarily focus on immediate patching and application updates to versions that properly implement input validation and format string handling. System administrators should prioritize updating licq installations to versions 1.0.5 or later where the buffer overflow has been addressed through proper bounds checking and input sanitization. Additionally, network administrators can implement firewall rules and access controls to limit communication with potentially compromised licq instances, though this represents a less secure mitigation approach compared to proper patching. The vulnerability demonstrates the importance of secure coding practices and adherence to security standards such as those recommended by the software engineering community, where proper input validation and memory management are fundamental requirements. Organizations should also consider implementing network monitoring and intrusion detection systems to identify potential exploitation attempts targeting this specific vulnerability. The ATT&CK framework categorizes this vulnerability under the T1203 - Exploitation for Client Execution technique, highlighting the need for comprehensive endpoint protection strategies that address both known and emerging threats in instant messaging applications.