CVE-2002-1456 in mIRC
Summary
by MITRE
Buffer overflow in mIRC 6.0.2 and earlier allows remote attackers to execute arbitrary code via a long $asctime value.
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Analysis
by VulDB Data Team • 06/28/2025
The vulnerability identified as CVE-2002-1456 represents a critical buffer overflow flaw within mIRC version 6.0.2 and earlier implementations. This issue specifically affects the handling of the $asctime identifier within the mIRC scripting environment, creating a pathway for remote attackers to execute arbitrary code on vulnerable systems. The mIRC client, widely used for internet relay chat communications, processes user input through its scripting capabilities, making it susceptible to malicious input manipulation. The buffer overflow occurs when the application encounters an excessively long $asctime value, which exceeds the allocated memory buffer size for processing this particular identifier.
This vulnerability operates at the intersection of several cybersecurity domains and can be classified under CWE-121, which addresses stack-based buffer overflow conditions. The flaw manifests when mIRC processes a crafted $asctime value that surpasses the predetermined buffer limits, leading to memory corruption that attackers can exploit to inject and execute malicious code. The attack vector is particularly concerning as it enables remote code execution without requiring local system access, making it a significant threat in networked environments where mIRC clients might be exposed to untrusted network traffic. The vulnerability affects the application's memory management and can result in unpredictable behavior including application crashes, data corruption, or complete system compromise.
The operational impact of this vulnerability extends beyond simple code execution, as it can enable attackers to gain persistent access to compromised systems and potentially escalate privileges. When exploited, the buffer overflow allows attackers to overwrite critical memory segments including return addresses and function pointers, thereby redirecting program execution flow. The vulnerability's remote exploitability means that attackers can leverage this flaw from outside the network, making it particularly dangerous in enterprise environments where mIRC clients might be used for communication. This type of vulnerability aligns with ATT&CK technique T1059.007, which covers script-based execution through command and scripting interpreters, and T1133, which involves external remote services. The attack can be classified as a privilege escalation vector, potentially allowing attackers to execute code with the privileges of the mIRC process, which typically runs with the user's permissions.
Mitigation strategies for CVE-2002-1456 should focus on immediate patching of affected mIRC versions, as the vulnerability has been addressed in subsequent releases. Organizations should implement network segmentation to limit exposure of mIRC clients to untrusted networks and consider disabling scripting features that process untrusted input. Additionally, security monitoring should include detection of unusual $asctime value patterns in network traffic and system logs. The vulnerability demonstrates the importance of proper input validation and memory management in client-side applications, particularly those handling user-generated content in chat and communication platforms. System administrators should also consider implementing application whitelisting policies to restrict execution of vulnerable mIRC versions and ensure that all client software receives regular security updates to prevent similar vulnerabilities from being exploited in the future.