CVE-2003-0323 in IrcII
Summary
by MITRE
Multiple buffer overflows in ircII 20020912 allows remote malicious IRC servers to cause a denial of service (crash) and possibly execute arbitrary code via responses that are not properly fed to the my_strcat function by (1) ctcp_buffer, (2) cannot_join_channel, (3) status_make_printable for Statusbar drawing, (4) create_server_list, and possibly other functions.
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Analysis
by VulDB Data Team • 04/22/2019
The vulnerability identified as CVE-2003-0323 represents a critical buffer overflow issue within the ircII IRC client version 20020912 that exposes multiple attack vectors through improper string handling mechanisms. This flaw affects the core functionality of the IRC client by creating conditions where maliciously crafted server responses can trigger memory corruption, leading to system instability and potential code execution. The vulnerability specifically targets the my_strcat function which serves as a fundamental string concatenation routine within the application's codebase, making it a prime target for exploitation by adversaries seeking to compromise IRC client installations.
The technical implementation of this vulnerability stems from inadequate input validation and buffer size management within several key functions of the ircII client. The ctcp_buffer function handles CTCP (Client-to-Client Protocol) responses which are commonly used for client identification and communication features within IRC networks. The cannot_join_channel handler processes server responses when users attempt to join channels, while status_make_printable manages the display of status information on the client's statusbar interface. The create_server_list function processes server connection information and network topology data. All these functions fail to properly validate the length of incoming data before passing it to the my_strcat function, which lacks sufficient bounds checking to prevent buffer overflows when concatenating strings.
From an operational standpoint, this vulnerability creates significant security implications for users of the ircII client, as it enables remote attackers to execute arbitrary code on vulnerable systems or cause complete client crashes. The attack vector requires a malicious IRC server to be present on the network, which means that users connecting to compromised IRC networks could be affected without any direct interaction from the user. The potential for code execution makes this vulnerability particularly dangerous as it could allow attackers to gain full control of the affected system, execute malicious payloads, or establish persistent access through backdoor mechanisms. The denial of service aspect prevents legitimate users from accessing IRC services, creating a disruption of communication channels that could be exploited for broader network attacks.
The vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios, both of which are common in applications that improperly handle string operations. From an ATT&CK framework perspective, this vulnerability maps to T1059.007 for command and scripting interpreter and T1499.004 for network denial of service, as it enables both arbitrary code execution and service disruption. The exploitability of this vulnerability is enhanced by the fact that it does not require user interaction beyond connecting to an IRC network, making it particularly dangerous in environments where users frequently connect to public IRC servers or networks with untrusted participants.
Mitigation strategies for this vulnerability should include immediate patching of the ircII client to address the buffer overflow conditions in the affected functions. System administrators should implement network segmentation to limit exposure to potentially malicious IRC servers and consider deploying network monitoring tools to detect unusual IRC traffic patterns. Additionally, users should be educated about the risks of connecting to untrusted IRC networks and the importance of keeping their IRC client software updated. The implementation of input validation controls and bounds checking mechanisms within the my_strcat function and related string handling routines would provide long-term protection against similar vulnerabilities. Organizations should also consider implementing network access controls to restrict IRC client connectivity to trusted networks and establish incident response procedures for handling potential exploitation attempts.