CVE-2001-1417 in Instant Messenger
Summary
by MITRE
AOL Instant Messenger (AIM) 4.7 allows remote attackers to cause a denial of service (application hang or crash) via a buddy icon GIF file whose length and width values are larger than the actual image data.
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Analysis
by VulDB Data Team • 11/13/2024
The vulnerability described in CVE-2001-1417 represents a classic buffer overflow condition affecting AOL Instant Messenger version 4.7, which falls under the broader category of software security flaws that can lead to denial of service attacks. This issue specifically targets the image parsing functionality within the instant messaging client, where the application fails to properly validate image dimensions before processing buddy icon files. The flaw demonstrates characteristics consistent with CWE-125, which describes out-of-bounds read conditions, and CWE-129, which covers insufficient validation of array indices. The vulnerability is particularly concerning as it allows remote attackers to exploit the application through crafted media files without requiring any special privileges or authentication.
The technical mechanism behind this vulnerability involves the improper handling of graphics interchange format files within the AIM client's buddy icon processing subsystem. When the application receives a buddy icon GIF file, it reads the image dimensions specified in the file header and allocates memory based on these reported values. However, the client does not validate whether the actual image data matches the declared dimensions, creating a scenario where the application attempts to read beyond allocated memory boundaries. This mismatch between declared and actual image data causes the application to crash or become unresponsive when attempting to render the malformed image, resulting in a denial of service condition that affects legitimate users of the messaging service.
From an operational perspective, this vulnerability presents significant risks to both individual users and organizations relying on AIM for communication. The attack vector is particularly dangerous because it can be executed remotely without requiring any user interaction beyond receiving a buddy icon from an attacker. The denial of service impact extends beyond simple application crashes, as the instability can potentially affect the entire messaging session and disrupt communication for all users within the affected network. This vulnerability aligns with ATT&CK technique T1499.004, which covers network denial of service, and represents a common exploitation pattern where attackers target application parsing functions to create system instability. The widespread adoption of AIM during this period meant that successful exploitation could affect large numbers of users simultaneously.
The remediation approach for this vulnerability requires immediate implementation of input validation measures within the application's image processing code. System administrators should prioritize updating to patched versions of AIM that properly validate image dimensions before memory allocation occurs. Additionally, network security measures such as content filtering and image validation proxies can provide additional layers of protection by screening incoming buddy icon files before they reach client applications. The fix typically involves implementing bounds checking and proper validation of image metadata, ensuring that declared dimensions match actual data content. Organizations should also consider implementing monitoring solutions to detect unusual patterns of application crashes or hangs that might indicate exploitation attempts, as this vulnerability represents a clear example of how malformed input data can be weaponized to disrupt legitimate services. The vulnerability demonstrates the importance of proper input sanitization and validation in preventing exploitation of parsing functions within client applications, particularly those handling user-generated content.