CVE-2008-1925 in InspIRCd
Summary
by MITRE
Buffer overflow in InspIRCd before 1.1.18, when using the namesx and uhnames modules, allows remote attackers to cause a denial of service (daemon crash) via a large number of channel users with crafted nicknames, idents, and long hostnames.
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Analysis
by VulDB Data Team • 08/10/2019
The vulnerability identified as CVE-2008-1925 represents a critical buffer overflow condition within the InspIRCd IRC server software that existed in versions prior to 1.1.18. This flaw specifically manifests when the server utilizes both the namesx and uhnames modules, which are designed to enhance channel user listing functionality and hostname handling respectively. The buffer overflow occurs due to insufficient input validation and boundary checking when processing large numbers of channel participants with specially crafted nickname, ident, and hostname values. The vulnerability operates at the protocol level where the IRC server processes user information during channel operations, creating an exploitable condition that can be triggered remotely without requiring authentication or privileged access.
The technical implementation of this vulnerability involves the improper handling of user data structures within the InspIRCd daemon's memory management system. When multiple users join a channel and their nicknames, idents, and hostnames are processed through the namesx and uhnames modules, the server fails to properly validate the length of these identifiers before storing them in fixed-size buffers. This condition creates a classic buffer overflow scenario where maliciously constructed user data can exceed the allocated buffer space, causing memory corruption that ultimately leads to daemon termination. The flaw specifically affects the server's ability to handle large channel user lists, making it particularly dangerous in environments with active channels containing numerous participants. The vulnerability operates under CWE-121, which classifies buffer overflow conditions where insufficient bounds checking allows memory corruption.
The operational impact of CVE-2008-1925 extends beyond simple denial of service, as it can be leveraged to disrupt IRC network services and potentially compromise server availability for legitimate users. Attackers can exploit this vulnerability by joining channels with crafted user identifiers that, when processed through the vulnerable modules, cause the InspIRCd daemon to crash and restart. This disruption can be particularly damaging in mission-critical IRC environments such as those used by development teams, gaming communities, or enterprise communication platforms where continuous service availability is essential. The vulnerability's remote exploitability means that attackers do not need physical access to the server or network privileges to cause disruption, making it a significant concern for server administrators. According to ATT&CK framework category T1499, this vulnerability aligns with network denial of service techniques that target service availability.
Mitigation strategies for CVE-2008-1925 require immediate implementation of the vendor-released patch for InspIRCd version 1.1.18 or later, which addresses the buffer overflow condition through proper input validation and enhanced memory management. System administrators should also implement monitoring solutions to detect unusual channel user join patterns that might indicate exploitation attempts. Additional defensive measures include disabling the namesx and uhnames modules if they are not essential for server operations, implementing rate limiting for channel user joins, and configuring proper access controls to limit the impact of potential exploitation. The vulnerability serves as a reminder of the importance of maintaining up-to-date software versions and the critical need for input validation in network services to prevent similar buffer overflow conditions from compromising system integrity. Organizations should also consider implementing intrusion detection systems that can identify patterns consistent with this specific attack vector and establish incident response procedures to quickly address potential exploitation attempts.