CVE-2000-0183 in IrcII
Summary
by MITRE
Buffer overflow in ircII 4.4 IRC client allows remote attackers to execute commands via the DCC chat capability.
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Analysis
by VulDB Data Team • 12/17/2024
The vulnerability identified as CVE-2000-0183 represents a critical buffer overflow flaw within the ircII 4.4 Internet Relay Chat client that specifically targets the DCC (Direct Client-to-Client) chat functionality. This vulnerability resides in the client's handling of incoming DCC chat requests and data transfers, creating a potential entry point for remote attackers to execute arbitrary commands on affected systems. The buffer overflow occurs when the ircII client processes maliciously crafted DCC chat messages that exceed the allocated buffer space, leading to memory corruption that can be exploited to gain unauthorized system access.
The technical implementation of this vulnerability stems from inadequate input validation and buffer management within the DCC chat processing module of the ircII client. When a remote attacker sends a specially crafted DCC chat message containing excessive data, the client fails to properly bounds-check the incoming data before copying it into fixed-size buffers. This fundamental flaw allows attackers to overwrite adjacent memory locations, potentially including return addresses on the stack, which can be manipulated to redirect program execution flow. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, representing a classic and well-documented software security weakness that has been extensively studied in cybersecurity literature. The attack vector is particularly dangerous because it leverages the trust relationship inherent in IRC communication protocols, where users expect to engage in legitimate chat sessions without anticipating malicious code execution.
The operational impact of this vulnerability extends beyond simple remote code execution, as it fundamentally compromises the security posture of systems running vulnerable ircII clients. An attacker who successfully exploits this vulnerability can gain full control over the affected system, potentially establishing persistent backdoors, escalating privileges, or using the compromised machine as a launch point for further attacks within a network. The DCC chat capability was designed for legitimate file transfers and direct communication between IRC users, making this attack vector particularly insidious as it operates within normal user expectations and network traffic patterns. This vulnerability has been documented in various security advisories and has been classified as a high-severity issue by multiple security organizations, highlighting its potential for widespread exploitation in environments where ircII clients are actively used. The attack can be executed without requiring any special privileges or authentication, making it particularly dangerous for systems where IRC clients are frequently used by multiple users.
Mitigation strategies for CVE-2000-0183 primarily focus on immediate software updates and operational security measures to prevent exploitation. The most effective remediation involves upgrading to a patched version of the ircII client that implements proper input validation and buffer management techniques. Organizations should also consider implementing network-level restrictions that disable DCC chat functionality entirely, as this capability is often unnecessary for many network environments and provides an unnecessary attack surface. Security monitoring should include detection of anomalous DCC chat traffic patterns and potential exploitation attempts. From a defensive perspective, this vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as successful exploitation would enable attackers to execute commands on compromised systems. System administrators should also consider implementing network segmentation and access controls to limit the potential impact of any successful exploitation, while maintaining regular security assessments to identify and remediate similar vulnerabilities in other network services and applications.