CVE-2010-0300 in ircd-ratbox
Summary
by MITRE
cache.c in ircd-ratbox before 2.2.9 allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a HELP command.
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Analysis
by VulDB Data Team • 04/30/2026
The vulnerability identified as CVE-2010-0300 resides within the ircd-ratbox IRC daemon software, specifically in the cache.c component of versions prior to 2.2.9. This represents a critical security flaw that can be exploited by remote attackers to disrupt service availability. The issue manifests when the daemon processes a malformed HELP command, triggering a null pointer dereference that ultimately leads to daemon crash and subsequent denial of service conditions for legitimate users.
The technical implementation of this vulnerability stems from inadequate input validation within the IRC daemon's command processing pipeline. When a remote attacker sends a specially crafted HELP command to the ircd-ratbox server, the cache.c module fails to properly handle the command parameters, resulting in a null pointer dereference during memory access operations. This type of error represents a classic software bug pattern that falls under the Common Weakness Enumeration category CWE-476, which specifically addresses null pointer dereference conditions. The flaw occurs because the software does not validate whether command arguments are properly initialized before attempting to access them, creating an execution path where a null pointer is dereferenced and causes the process to terminate abruptly.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the stability and availability of IRC networks that rely on affected ircd-ratbox implementations. When exploited successfully, the denial of service condition can render entire IRC channels or networks inaccessible to legitimate users, disrupting communication channels that may be critical for various organizational functions. Network administrators and system operators who depend on these IRC services for real-time communication, coordination, or information sharing face significant operational challenges when such vulnerabilities are present in their infrastructure. The attack vector requires minimal technical expertise from the attacker, as the exploit can be executed through standard IRC client commands, making this vulnerability particularly dangerous in environments where network access is not strictly controlled.
Mitigation strategies for CVE-2010-0300 should prioritize immediate patch deployment to upgrade affected ircd-ratbox installations to version 2.2.9 or later, which contains the necessary code modifications to properly handle malformed HELP commands. Additionally, network administrators should implement monitoring solutions to detect unusual command patterns that may indicate exploitation attempts, while also considering network-level firewalls or intrusion detection systems that can filter suspicious IRC traffic. The vulnerability's classification under the ATT&CK framework would place it within the T1499 category for Network Denial of Service, emphasizing the need for both preventive measures and incident response capabilities. Organizations should also conduct comprehensive vulnerability assessments of their IRC infrastructure to identify any other potentially affected components, as this type of input validation flaw may exist in other parts of the software stack. Regular security updates and patch management processes become essential to prevent similar vulnerabilities from compromising service availability in the future.