CVE-2007-2809 in Web Browser
Summary
by MITRE
Buffer overflow in the transfer manager in Opera before 9.21 for Windows allows user-assisted remote attackers to execute arbitrary code via a crafted torrent file. NOTE: due to the lack of details, it is not clear if this is the same issue as CVE-2007-2274.
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Analysis
by VulDB Data Team • 06/08/2025
The vulnerability identified as CVE-2007-2809 represents a critical buffer overflow flaw within Opera's transfer manager component affecting versions prior to 9.21 on Windows operating systems. This security weakness resides in the handling of torrent files, specifically within the client-side torrent management functionality that processes peer-to-peer file sharing requests. The buffer overflow occurs when Opera processes specially crafted torrent files that contain malformed data structures exceeding the allocated buffer space. The flaw enables user-assisted remote attackers to exploit this vulnerability by delivering malicious torrent files through various means including web downloads, email attachments, or peer-to-peer networks where torrent files are commonly shared.
The technical implementation of this vulnerability falls under the CWE-121 category of stack-based buffer overflow, where insufficient bounds checking allows attackers to overwrite adjacent memory locations within the application's execution context. When Opera's transfer manager attempts to parse the crafted torrent file, the buffer overflow can corrupt stack variables, return addresses, and other critical memory structures. This memory corruption can lead to arbitrary code execution with the privileges of the user running the Opera browser, potentially allowing attackers to gain complete control over the affected system. The vulnerability's exploitation requires a user to interact with a malicious torrent file, making it a user-assisted remote code execution vulnerability rather than a fully autonomous attack vector.
The operational impact of CVE-2007-2809 extends beyond simple code execution, as it represents a significant threat to user security and system integrity within peer-to-peer file sharing environments. The vulnerability affects not only individual users who may inadvertently download malicious torrents but also creates potential risks for organizations that may have employees using Opera for file sharing activities. Attackers could leverage this vulnerability to install malware, establish backdoors, or perform other malicious activities on compromised systems. The attack surface is particularly concerning given the widespread use of torrent clients and the nature of peer-to-peer file sharing networks where users frequently download content from untrusted sources.
Organizations and individual users should prioritize immediate remediation by upgrading to Opera version 9.21 or later, which contains the necessary patches to address this buffer overflow vulnerability. The mitigation strategy should include comprehensive security awareness training for users to recognize potentially malicious torrent files and avoid downloading content from untrusted sources. Network administrators should implement content filtering solutions to block suspicious torrent file downloads and monitor for unusual peer-to-peer traffic patterns. Additionally, system hardening measures such as disabling automatic torrent file handling, implementing application whitelisting policies, and maintaining current antivirus signatures can provide additional layers of protection against exploitation attempts. The vulnerability demonstrates the importance of proper input validation and bounds checking in client-side applications, particularly those handling untrusted data from external sources, aligning with ATT&CK technique T1059.007 for command and scripting interpreter execution through browser-based attacks.