CVE-2003-1503 in Instant Messenger
Summary
by MITRE
Buffer overflow in AOL Instant Messenger (AIM) 5.2.3292 allows remote attackers to execute arbitrary code via an aim:getfile URL with a long screen name.
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Analysis
by VulDB Data Team • 03/08/2021
The vulnerability identified as CVE-2003-1503 represents a critical buffer overflow flaw in AOL Instant Messenger version 5.2.3292 that exposes users to remote code execution risks. This issue stems from inadequate input validation within the application's handling of aim:getfile URLs, specifically when processing screen names that exceed predetermined buffer limits. The flaw occurs when the application fails to properly sanitize or truncate user-supplied screen name data before copying it into fixed-length memory buffers, creating conditions where maliciously crafted input can overwrite adjacent memory locations.
The technical implementation of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory regions. When a remote attacker crafts a malicious aim:getfile URL containing an excessively long screen name parameter, the AIM client processes this input without adequate validation, leading to memory corruption that can be exploited to redirect program execution flow. The attack vector specifically targets the URL handling mechanism within the AIM client, leveraging the protocol's inherent trust in locally generated URLs to execute malicious code with the privileges of the targeted user.
From an operational perspective, this vulnerability presents significant risk to users of the affected AIM version, as it enables remote code execution without requiring user interaction beyond visiting a malicious website or receiving a specially crafted instant message. The exploitability of this flaw increases substantially given that AIM was widely deployed in enterprise and personal environments during this period, making the attack surface extensive. Attackers can leverage this vulnerability to install malware, steal credentials, or establish persistent access to compromised systems. The impact extends beyond individual user compromise to potentially enable broader network infiltration, particularly in environments where AIM was used as a primary communication tool.
The mitigation strategies for CVE-2003-1503 should prioritize immediate application of vendor patches and updates to the AIM client software, as the vulnerability was addressed through proper input validation and buffer size enforcement. Organizations should implement network-based controls to monitor and block suspicious aim:getfile URL patterns, while also considering the deployment of web application firewalls to filter malicious content. Additionally, user education regarding the dangers of visiting untrusted websites and clicking on suspicious instant messages remains crucial. The ATT&CK framework categorizes this vulnerability under T1059 for command and script interpreter usage, as exploitation typically involves executing malicious code through the compromised application. Security teams should also consider implementing runtime application self-protection mechanisms and regular vulnerability assessments to identify similar buffer overflow conditions in other legacy applications that may be similarly susceptible to remote code execution attacks.