CVE-2003-1188 in Unichat
Summary
by MITRE
Unichat allows remote attackers to cause a denial of service (crash) by adding extra chat characters (avatars) and logging in to a chat room, as demonstrated using duplicate ACTOR entries in u2res000.rit.
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Analysis
by VulDB Data Team • 06/15/2018
The vulnerability described in CVE-2003-1188 represents a classic denial of service flaw within the Unichat messaging system that demonstrates poor input validation and resource management practices. This vulnerability specifically targets the chat room authentication and avatar handling mechanisms, where attackers can exploit the system's failure to properly validate or limit the number of avatar entries during user login processes. The issue manifests when duplicate ACTOR entries are present in the u2res000.rit resource file, creating a condition where the system becomes unstable and eventually crashes when processing these malformed inputs.
The technical implementation of this vulnerability leverages the system's reliance on resource files for user identification and display purposes. When Unichat processes login requests, it reads from the u2res000.rit file which contains ACTOR entries that define user avatars and their associated properties. The flaw occurs because the system does not adequately validate the structure or content of these entries, particularly when duplicate or malformed ACTOR entries exist. This allows an attacker to craft malicious login sequences that cause the application to enter an infinite loop or memory exhaustion state when attempting to process the duplicate entries, ultimately leading to a complete system crash and denial of service for legitimate users.
From an operational perspective, this vulnerability presents a significant risk to chat room availability and user experience, as it can be exploited by remote attackers without requiring any special privileges or authentication. The impact extends beyond simple service disruption to potentially affecting the entire communication infrastructure that relies on the Unichat system. The vulnerability's exploitation is particularly concerning because it requires minimal technical expertise to execute, making it attractive to attackers seeking to disrupt services. This type of vulnerability aligns with CWE-129, which describes improper validation of input boundaries, and represents a failure in the system's defensive programming practices that should prevent malformed data from causing system instability.
The attack vector for this vulnerability operates through the standard chat room login process, where an attacker can manipulate the u2res000.rit file or influence its contents to include duplicate ACTOR entries. This allows the attacker to trigger the denial of service condition during normal user authentication flows, effectively making the chat room unavailable to legitimate users. The vulnerability demonstrates a lack of proper resource management and input sanitization that is fundamental to secure system design. Organizations using Unichat systems would be advised to implement immediate mitigations including input validation for resource files, limiting the number of duplicate entries allowed, and implementing proper error handling that prevents system crashes from malformed inputs. The flaw also highlights the importance of the principle of least privilege in system design, where resource files should be protected from unauthorized modification that could lead to system instability.
This vulnerability serves as a reminder of the critical importance of secure input handling and resource management in communication systems. The flaw's classification under CWE-129 indicates that it stems from inadequate boundary checking and input validation, which are fundamental security practices that should be implemented at every level of system development. The ATT&CK framework would categorize this as a system service denial of service attack, where an adversary leverages weaknesses in application logic to disrupt service availability. Organizations should consider implementing additional monitoring and alerting mechanisms to detect unusual patterns in chat room access or resource file modifications that could indicate exploitation attempts. The vulnerability also underscores the need for regular security assessments and code reviews to identify similar input validation weaknesses that could lead to system instability and service disruption.