CVE-2003-1512 in mIRC
Summary
by MITRE
Buffer overflow in mIRC 6.1 and 6.11 allows remote attackers to cause a denial of service (crash) via a long DCC SEND request.
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Analysis
by VulDB Data Team • 02/02/2025
The vulnerability identified as CVE-2003-1512 represents a critical buffer overflow flaw affecting mIRC versions 6.1 and 6.11, specifically within the DCC SEND functionality of the popular internet relay chat client. This issue stems from inadequate input validation mechanisms that fail to properly handle excessively long data transmission requests, creating a condition where malicious actors can exploit the software's memory management to trigger unintended behavior.
The technical implementation of this vulnerability occurs when mIRC processes incoming DCC SEND requests, which are typically used for direct file transfers between users in IRC networks. The flaw manifests as a classic stack-based buffer overflow where the application fails to validate the length of data contained within the DCC SEND command before attempting to copy it into a fixed-size memory buffer. This allows an attacker to overwrite adjacent memory locations, potentially corrupting program execution flow and causing the application to crash or behave unpredictably. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, which directly maps to the attack pattern described in the ATT&CK framework under T1499.004 for network denial of service attacks.
The operational impact of this vulnerability extends beyond simple service disruption, as it enables remote attackers to systematically crash mIRC clients across IRC networks without requiring any special privileges or authentication. This creates a significant risk for users who rely on mIRC for communication, particularly in environments where continuous connectivity is essential. The attack vector is particularly dangerous because it can be executed remotely without the need for user interaction, making it an ideal candidate for automated exploitation across multiple targets simultaneously. The vulnerability affects not only individual users but also network administrators who must maintain service availability for their communities.
Mitigation strategies for CVE-2003-1512 should prioritize immediate software updates to patched versions of mIRC, as the original developers released fixes addressing the buffer overflow condition. Network administrators should implement monitoring solutions to detect unusual DCC SEND traffic patterns that might indicate exploitation attempts. Additionally, users should be educated about the risks of accepting file transfers from untrusted sources, as this vulnerability can be exploited through social engineering tactics. The implementation of input validation controls and boundary checking mechanisms within the application code represents the fundamental fix required to address this vulnerability, aligning with industry best practices for secure coding standards and the principle of least privilege in network security management.