CVE-2002-2156 in Trillian
Summary
by MITRE
Buffer overflow in Trillian 0.73 allows remote IRC servers to execute arbitrary code via a long PING response.
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Analysis
by VulDB Data Team • 06/11/2018
The vulnerability identified as CVE-2002-2156 represents a critical buffer overflow flaw in Trillian 0.73 instant messaging client that specifically affects the IRC protocol implementation. This vulnerability arises from inadequate input validation within the client's handling of PING responses from IRC servers, creating a condition where malicious actors can exploit the software's memory management to execute arbitrary code on affected systems. The flaw exists in the client's network communication layer where it processes server responses without proper bounds checking, allowing attackers to craft specially formatted PING responses that exceed the allocated buffer space.
The technical exploitation of this vulnerability occurs when a remote IRC server sends a malformed PING response containing excessive data that overflows the designated buffer in Trillian's memory allocation. This buffer overflow creates a situation where adjacent memory locations are overwritten, potentially allowing an attacker to inject and execute malicious code with the privileges of the affected user. The vulnerability is classified as a classic stack-based buffer overflow under CWE-121, which specifically addresses the condition where insufficient bounds checking allows memory to be overwritten beyond allocated limits. The attack vector is remote and requires no authentication, making it particularly dangerous as it can be exploited by anyone who can connect to the victim's IRC client.
The operational impact of CVE-2002-2156 extends beyond simple code execution to encompass potential system compromise and data theft. When successfully exploited, the vulnerability allows attackers to gain arbitrary code execution, which could lead to complete system compromise, privilege escalation, or the installation of persistent backdoors. The vulnerability affects users who are connected to IRC networks and have Trillian 0.73 installed, making it particularly concerning for users who connect to public or untrusted IRC servers. This vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as the successful exploitation would enable attackers to execute commands through the compromised client. The attack requires minimal user interaction beyond connecting to an IRC server, making it a significant threat to users who maintain active IRC connections.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term security posture improvements. The primary solution involves updating to a patched version of Trillian that implements proper input validation and bounds checking for PING responses. System administrators should also implement network segmentation and firewall rules to limit IRC traffic access, particularly when connecting to untrusted servers. Network monitoring should be enhanced to detect unusual PING response patterns that might indicate exploitation attempts. Additionally, users should be educated about the risks of connecting to untrusted IRC servers and the importance of keeping instant messaging clients updated. The vulnerability highlights the critical importance of input validation in network applications and demonstrates how seemingly benign protocol features can become attack vectors when proper security controls are not implemented. Organizations should also consider implementing application whitelisting policies to prevent unauthorized versions of Trillian from executing on their networks.