CVE-2002-1967 in Xircon
Summary
by MITRE
Buffer overflow in XiRCON 1.0 Beta 4 allows remote attackers to cause a denial of service (disconnect) via a long (1) ctcp, (2) primsg, (3) msg, or (4) notice command.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 07/07/2024
The vulnerability identified as CVE-2002-1967 represents a critical buffer overflow flaw within the XiRCON 1.0 Beta 4 IRC client software that exposes remote attackers to significant operational risks. This vulnerability specifically affects the handling of four distinct command types including ctcp, primsg, msg, and notice commands, each of which can be exploited to trigger the buffer overflow condition. The flaw stems from inadequate input validation mechanisms within the client's command processing pipeline, where the software fails to properly sanitize or limit the length of incoming data before attempting to store it in fixed-size memory buffers. This particular implementation vulnerability aligns with CWE-121, which categorizes buffer overflow conditions occurring when insufficient space is allocated for data, or when data exceeds the allocated buffer boundaries. The affected commands are fundamental to IRC communication protocols, making this vulnerability particularly dangerous as it can be triggered through normal chat interactions, potentially allowing attackers to disrupt service availability for legitimate users.
The technical exploitation of this vulnerability occurs when remote attackers craft maliciously long command strings that exceed the allocated buffer space in the XiRCON client's memory management system. When the client processes these oversized commands, the excess data overflows into adjacent memory regions, causing unpredictable behavior and ultimately leading to application termination or system instability. The denial of service condition manifests as client disconnections from IRC networks, effectively preventing users from maintaining their chat sessions and accessing network resources. This type of attack falls under the ATT&CK technique T1499.004, which describes network disruption attacks targeting communication protocols and services. The buffer overflow occurs during the parsing phase of IRC command processing, where the client's memory allocation strategy does not account for the possibility of maliciously extended input strings, creating a predictable exploitation vector that requires no authentication or privileged access.
The operational impact of CVE-2002-1967 extends beyond simple service disruption to potentially compromise the broader IRC network ecosystem where affected clients operate. When exploited, this vulnerability can cause cascading effects as disconnected users may attempt to reconnect repeatedly, potentially overwhelming network resources and creating additional service degradation. The vulnerability's exposure through standard IRC communication channels means that any user connecting to a network where vulnerable clients exist becomes a potential target for this attack, as the malicious input can be delivered through normal chat operations without requiring specialized attack tools. Organizations and network administrators must consider the implications of this vulnerability when managing IRC client deployments, particularly in environments where multiple users interact through shared network connections. The flaw represents a fundamental security weakness in input handling that could potentially be extended to other similar buffer overflow scenarios, making it a critical area for system hardening and application security reviews. The vulnerability's classification as a remote attack vector means that threat actors can exploit it from anywhere on the internet without requiring physical access to the target system, making it particularly concerning for organizations that rely on IRC for communication or collaboration purposes. Mitigation strategies should include immediate client updates, network monitoring for suspicious command patterns, and implementation of input validation controls to prevent oversized command processing.