CVE-2002-2329 in ICQ
Summary
by MITRE
ICQ client 2001b, 2002a and 2002b allows remote attackers to cause a denial of service (CPU consumption or crash) via a message with a large number of emoticons.
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Analysis
by VulDB Data Team • 07/13/2024
The vulnerability described in CVE-2002-2329 represents a classic denial of service flaw affecting multiple versions of the ICQ instant messaging client. This issue specifically targets the client's message parsing functionality where the software fails to properly handle messages containing an excessive number of emoticons. The vulnerability stems from inadequate input validation and processing logic within the ICQ client's message handling code, which does not implement proper bounds checking or resource limitation mechanisms when processing user-generated content. The flaw exists in versions 2001b, 2002a, and 2002b of the ICQ client, indicating this was a persistent issue across a range of releases that was not adequately addressed by the developers.
The technical implementation of this vulnerability exploits the client's failure to limit the number of emoticons processed in a single message. When a malicious user sends a message containing thousands or tens of thousands of emoticons, the ICQ client's parsing routine becomes overwhelmed with processing tasks. The client attempts to render each emoticon individually, leading to exponential CPU consumption as the parsing algorithm iterates through the massive emoticon sequence. This creates a resource exhaustion condition where the client's processing threads become saturated, causing either complete application crashes or sustained high CPU utilization that renders the client unusable. The vulnerability operates at the application layer and does not require any special privileges or authentication to exploit, making it particularly dangerous as it can be triggered by any remote user with access to the target client's communication channel.
The operational impact of CVE-2002-2329 extends beyond simple service disruption to potentially compromise user productivity and system stability. When exploited successfully, the vulnerability can cause immediate denial of service for the targeted ICQ client, forcing users to restart their applications or even reboot their systems to restore normal operation. In enterprise environments where ICQ clients are used for business communication, this vulnerability could lead to significant operational disruptions and loss of productivity. The attack vector is particularly concerning because it can be executed silently and automatically, allowing an attacker to repeatedly send malicious messages without detection. From a cybersecurity perspective, this vulnerability demonstrates the importance of proper input sanitization and resource management in client-side applications, as it highlights how seemingly benign features like emoticon support can become attack vectors when not properly constrained.
This vulnerability aligns with CWE-400, which describes "Uncontrolled Resource Consumption" or "Resource Exhaustion" in software systems, and represents a specific implementation where the resource exhaustion occurs through excessive parsing of user input. The attack pattern follows the techniques outlined in the ATT&CK framework under the T1499.004 subtechnique "Resource Hijacking" where adversaries consume system resources to deny service to legitimate users. The vulnerability also relates to CWE-129, "Improper Validation of Array Index," as the client fails to validate the array bounds when processing emoticon sequences. Effective mitigations should include implementing maximum emoticon limits per message, introducing rate limiting for incoming messages, and implementing proper memory management to prevent excessive CPU consumption. Additionally, the fix should involve robust input validation that prevents processing of messages exceeding predetermined thresholds for emoticon count, ensuring that even malformed or malicious input cannot cause the client to consume excessive resources and maintain system stability.