CVE-2002-2155 in Trillian
Summary
by MITRE
Format string vulnerability in the error handling of IRC invite responses for Trillian 0.725 and 0.73 allows remote IRC servers to execute arbitrary code via an invite to a channel with format string specifiers in the name.
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Analysis
by VulDB Data Team • 07/11/2024
The vulnerability identified as CVE-2002-2155 represents a critical format string flaw within the Trillian instant messaging client version 0.725 and 0.73, specifically affecting the error handling mechanism for IRC invite responses. This vulnerability arises from the application's improper validation and processing of user-supplied data during the invitation process, creating a path for remote code execution through carefully crafted malicious input. The flaw manifests when Trillian receives an IRC invite command containing format string specifiers in the channel name, which the application fails to properly sanitize or escape before processing.
The technical exploitation of this vulnerability occurs through the manipulation of the IRC protocol's invite command, where remote servers can inject format string specifiers such as %s, %x, or %n into channel names. When Trillian's error handling code attempts to display these malformed channel names, the format string vulnerability allows attackers to control the execution flow by writing data to arbitrary memory locations. This type of vulnerability falls under the Common Weakness Enumeration category CWE-134, which specifically addresses the use of format strings with user-supplied data, making it a direct descendant of the broader class of injection vulnerabilities that have plagued software systems for decades.
The operational impact of this vulnerability extends beyond simple remote code execution, as it enables attackers to potentially overwrite critical program memory, execute arbitrary commands with the privileges of the Trillian process, and ultimately compromise the entire system. The vulnerability is particularly dangerous because it operates at the application level, requiring no special privileges to exploit and allowing attackers to leverage the legitimate IRC protocol functionality to gain unauthorized access. This weakness directly maps to the attack technique described in the MITRE ATT&CK framework under T1059.007 for Command and Scripting Interpreter, where attackers leverage application vulnerabilities to execute malicious commands.
Mitigation strategies for this vulnerability should focus on immediate patching of the Trillian client to version 0.731 or later, which includes proper input sanitization and format string handling. Additionally, system administrators should implement network-level restrictions to prevent unauthorized IRC servers from connecting to internal Trillian clients, particularly in enterprise environments where such clients might be used for business communication. The vulnerability highlights the importance of proper input validation and the application of secure coding practices, specifically the avoidance of direct string concatenation with user-supplied data in format string operations. Organizations should also consider implementing intrusion detection systems to monitor for unusual IRC protocol traffic patterns that might indicate exploitation attempts, and conduct regular security assessments of third-party applications to identify similar vulnerabilities in other instant messaging clients that might be susceptible to the same class of attack.