CVE-2006-0489 in mIRC
Summary
by MITRE
** DISPUTED ** Buffer overflow in the font command of mIRC, probably 6.16, allows local users to execute arbitrary code via a long string. NOTE: the original researcher claims that issue has been disputed by the vendor, and that the vendor stated "as far as I can tell, this is neither an exploit nor a vulnerability. The above report describes a local bug in mIRC." It could be that this is only exploitable by the user of the application, and thus would not cross privilege boundaries unless under an otherwise restrictive environment such as a kiosk.
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Analysis
by VulDB Data Team • 08/07/2024
The vulnerability identified as CVE-2006-0489 pertains to a buffer overflow condition within the font command implementation of mIRC version 6.16. This issue resides in the client-side messaging application that was widely used for internet relay chat communications during the mid-2000s period. The buffer overflow represents a classic software security flaw where an attacker can write more data to a fixed-length buffer than it can accommodate, potentially overwriting adjacent memory locations and allowing for arbitrary code execution.
The technical flaw manifests specifically when processing font commands within mIRC's scripting environment, where a local user can craft a specially formatted string that exceeds the allocated buffer space. This condition creates a potential code execution vector that could be exploited to run malicious code with the privileges of the mIRC process. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, which occurs when insufficient bounds checking allows data to overwrite adjacent stack memory, potentially corrupting program execution flow.
From an operational perspective, the impact of this vulnerability is constrained by its local nature and the specific privilege boundaries of the mIRC application. The vendor's disputed stance suggests that exploitation would require the attacker to already have user-level access to the system where mIRC is running, making this a privilege escalation issue only within the context of existing user access. This limitation aligns with ATT&CK technique T1068 which describes local privilege escalation and T1059 which covers command and scripting interpreters, as the vulnerability involves command processing within a scripting environment.
The security implications extend beyond simple code execution as this vulnerability demonstrates how client-side applications can become attack vectors when they fail to properly validate input parameters. The mIRC application's font command processing does not adequately sanitize user-provided strings, creating a path where malicious input can manipulate memory layout and potentially redirect program execution. This flaw represents a failure in input validation and memory management practices that were common in software development during the early 2000s era.
Mitigation strategies for this vulnerability would primarily focus on input validation and bounds checking within the application's command processing subsystem. The most effective approach involves implementing proper buffer size validation before processing font commands, ensuring that input strings are truncated or rejected if they exceed safe limits. Additionally, developers should employ stack canaries, address space layout randomization, and other modern exploit mitigation techniques. The vendor's position that this is not a vulnerability in their assessment suggests that proper input sanitization and bounds checking should be implemented to prevent such conditions from occurring in the first place, aligning with security best practices outlined in the OWASP Top Ten and NIST cybersecurity frameworks.