CVE-2009-1831 in WinAmp
Summary
by MITRE
The Nullsoft Modern Skins Support module (gen_ff.dll) in Nullsoft Winamp before 5.552 allows remote attackers to execute arbitrary code via a crafted MAKI file, which triggers an incorrect sign extension, an integer overflow, and a stack-based buffer overflow.
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Analysis
by VulDB Data Team • 04/10/2025
The vulnerability identified as CVE-2009-1831 represents a critical security flaw within the Nullsoft Winamp media player software, specifically within its Modern Skins Support module known as gen_ff.dll. This vulnerability affects Winamp versions prior to 5.552 and presents a significant risk to users who may inadvertently encounter maliciously crafted files. The flaw resides in how the software processes MAKI files, which are used for skinning and customization purposes within the media player environment.
The technical exploitation of this vulnerability involves a sophisticated chain of memory corruption issues that begin with incorrect sign extension within the processing logic. This initial flaw leads to an integer overflow condition that fundamentally compromises the memory management within the application. The overflow subsequently triggers a stack-based buffer overflow, creating an exploitable condition where attacker-controlled data can overwrite critical memory regions. The combination of these vulnerabilities creates a perfect storm for remote code execution, as the buffer overflow allows malicious code to be injected directly into the application's execution context. This type of vulnerability is classified under CWE-121 as a stack-based buffer overflow, and it aligns with ATT&CK technique T1059.007 for command and scripting interpreter.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with complete control over the affected system when a user opens a maliciously crafted MAKI file. The remote exploitation capability means that attackers can deliver these payloads through various vectors including email attachments, malicious websites, or file sharing platforms. Once executed, the malicious code can perform actions such as installing additional malware, stealing user data, or establishing persistent access to the compromised system. The vulnerability's severity is amplified by the widespread use of Winamp and the fact that the exploitation does not require any special privileges or user interaction beyond simply opening the malicious file.
Mitigation strategies for CVE-2009-1831 primarily focus on immediate software updates and patches provided by Nullsoft to address the underlying memory corruption issues. Users should ensure their Winamp installations are updated to version 5.552 or later, which contains the necessary fixes for the integer overflow and buffer overflow conditions. Additionally, system administrators should implement strict file validation policies and consider sandboxing mechanisms for media player applications to limit potential damage from successful exploits. Network-level protections such as content filtering and email scanning can help prevent the delivery of malicious MAKI files to end users. The vulnerability also highlights the importance of input validation and proper memory management practices in software development, particularly for applications that process user-supplied data files. Organizations should conduct regular security assessments of legacy software components and implement robust application whitelisting policies to prevent execution of untrusted media files. This vulnerability serves as a reminder of the critical need for maintaining up-to-date software and implementing defense-in-depth strategies to protect against sophisticated exploitation techniques.