CVE-2004-2529 in Instant Messenger
Summary
by MITRE
Gadu-Gadu allows remote attackers to bypass the "image send" option by sending a very small image file, which could be used in conjunction with image-related vulnerabilities.
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Analysis
by VulDB Data Team • 07/19/2017
The vulnerability described in CVE-2004-2529 affects the Gadu-Gadu instant messaging protocol implementation which was widely used in Eastern European markets. This security flaw represents a bypass issue that specifically targets the image sending functionality within the messaging system, creating a potential pathway for remote attackers to circumvent intended security controls. The vulnerability operates through a specific technical mechanism involving image file size manipulation that undermines the protocol's intended access controls.
The technical implementation of this vulnerability stems from inadequate input validation within the Gadu-Gadu client software. When users attempt to send images through the messaging protocol, the system should enforce certain size limitations and validation checks to prevent malicious content from being transmitted. However, the flaw allows attackers to exploit a weakness in the validation process by sending extremely small image files that are below the normal size thresholds expected by the protocol. This bypass occurs because the system fails to properly validate the image content itself, focusing instead on size parameters that can be easily manipulated.
From an operational perspective, this vulnerability creates significant security implications for users of the Gadu-Gadu messaging system. The bypass mechanism could enable attackers to circumvent intended restrictions on image transmission, potentially allowing them to send malicious content or exploit other image-related vulnerabilities that exist within the system. The small file size manipulation technique represents a common attack vector that has been documented in various network protocols where size-based validation is insufficient to prevent malicious activity. This type of vulnerability falls under the category of insufficient input validation as classified by CWE-20, which is a fundamental weakness in software security design.
The impact of this vulnerability extends beyond simple bypass functionality, as it creates potential opportunities for more sophisticated attacks within the messaging environment. Attackers could combine this bypass with other image-related vulnerabilities to execute malicious code or gain unauthorized access to user systems. The attack surface is particularly concerning because instant messaging protocols often handle multimedia content that can contain executable code or be used to deliver phishing content. This vulnerability demonstrates how seemingly minor implementation flaws in protocol handling can create significant security risks for end users.
Security mitigations for this vulnerability should focus on implementing comprehensive input validation that goes beyond simple size checks to include content analysis and proper image format validation. The fix should enforce strict validation of image file properties including but not limited to file headers, dimensions, and actual content structure to prevent the bypass mechanism. Organizations using Gadu-Gadu systems should implement network monitoring to detect unusual image transmission patterns and ensure that all client implementations properly validate image content regardless of file size. This vulnerability also highlights the importance of following secure coding practices and adhering to established security frameworks that prevent such input validation weaknesses from being introduced into network protocols. The ATT&CK framework would categorize this as a technique involving input validation bypass, potentially leading to privilege escalation or code execution through image handling components.