CVE-2000-0586 in IRCd
Summary
by MITRE
Buffer overflow in Dalnet IRC server 4.6.5 allows remote attackers to cause a denial of service or execute arbitrary commands via the SUMMON command.
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Analysis
by VulDB Data Team • 12/10/2024
The vulnerability identified as CVE-2000-0586 represents a critical buffer overflow flaw within the Dalnet IRC server version 4.6.5 that exposes the system to remote exploitation. This issue specifically manifests through the SUMMON command implementation, which fails to properly validate input length before processing user-supplied data. The flaw occurs when the server receives a malformed SUMMON command containing excessive data that exceeds the allocated buffer size, leading to memory corruption and potential arbitrary code execution. Such buffer overflow conditions are classified under CWE-121 as stack-based buffer overflow, where insufficient bounds checking allows attackers to overwrite adjacent memory locations including return addresses and control data. The vulnerability presents a significant risk to IRC server stability and security as it enables remote attackers to either crash the server through denial of service or potentially gain unauthorized system access by executing malicious code within the server process context.
The operational impact of this vulnerability extends beyond simple service disruption to encompass potential complete system compromise. When exploited successfully, the buffer overflow allows attackers to manipulate the program execution flow by overwriting the return address on the stack, which can redirect execution to malicious code injected into the buffer space. This type of exploitation aligns with ATT&CK technique T1059.007 for command and scripting interpreter and T1203 for exploitation for privilege escalation. The denial of service aspect can be achieved through simple command injection that causes the server process to terminate unexpectedly, while the arbitrary code execution capability enables attackers to establish persistent access to the compromised system. The vulnerability affects systems running Dalnet IRC server 4.6.5 and potentially other versions with similar implementation flaws in their SUMMON command handling. The attack vector requires minimal privileges as the vulnerability is accessible through standard IRC client connections, making it particularly dangerous for public-facing IRC servers that serve multiple users.
Mitigation strategies for CVE-2000-0586 should prioritize immediate patching of the affected Dalnet IRC server software to address the buffer overflow in the SUMMON command implementation. Organizations should implement network-level protections such as firewall rules that restrict access to IRC server ports from untrusted networks, particularly limiting the attack surface by not exposing the server directly to the internet. Input validation measures should be strengthened to enforce strict length limits on all command parameters, with the server rejecting any SUMMON command exceeding predetermined safe buffer sizes. System administrators should consider implementing intrusion detection systems that monitor for suspicious IRC traffic patterns and malformed SUMMON commands. Additionally, regular security audits and code reviews should be conducted to identify similar buffer overflow vulnerabilities in other server components, with proper memory management practices such as using safe string handling functions and implementing stack canaries. The vulnerability also highlights the importance of maintaining up-to-date software versions and applying security patches promptly to prevent exploitation of known vulnerabilities. Organizations should also implement proper logging and monitoring to detect potential exploitation attempts and maintain detailed audit trails for forensic analysis. The remediation process should include comprehensive testing to ensure that the patch does not introduce new functionality issues while effectively addressing the buffer overflow condition.