CVE-2008-4434 in uTorrent
Summary
by MITRE
Stack-based buffer overflow in (1) uTorrent 1.7.7 build 8179 and earlier and (2) BitTorrent 6.0.3 build 8642 and earlier allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a long Created By field in a .torrent file.
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Analysis
by VulDB Data Team • 05/25/2025
The vulnerability described in CVE-2008-4434 represents a critical stack-based buffer overflow affecting popular BitTorrent clients including uTorrent 1.7.7 build 8179 and earlier versions, as well as BitTorrent 6.0.3 build 8642 and earlier. This flaw resides in the handling of torrent file metadata, specifically within the parsing of the Created By field that is part of the .torrent file structure. The vulnerability stems from inadequate input validation and bounds checking when processing user-supplied data from torrent files, creating an exploitable condition where maliciously crafted input can overwrite adjacent memory on the stack.
The technical implementation of this vulnerability involves the client application failing to properly validate the length of the Created By field in torrent files before attempting to copy this data into a fixed-size stack buffer. When an attacker crafts a torrent file containing an excessively long Created By field, the application's buffer management fails to prevent the overflow, leading to memory corruption that can result in application crashes or potentially arbitrary code execution. This type of vulnerability falls under the CWE-121 stack-based buffer overflow category, which is classified as a serious memory safety issue that can be exploited by attackers to gain control over the affected system. The attack vector is remote and requires only that a victim opens a maliciously crafted torrent file, making it particularly dangerous in peer-to-peer environments where users frequently download torrents from untrusted sources.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it creates potential for remote code execution in vulnerable configurations. When exploited successfully, the buffer overflow can allow attackers to inject and execute malicious code within the context of the BitTorrent client process, potentially leading to complete system compromise. The vulnerability affects the core functionality of these applications and represents a significant risk to users who regularly download torrents, as the attack requires no special privileges or local access to the target system. Users may inadvertently encounter this vulnerability through legitimate torrent files that have been tampered with by attackers or through maliciously crafted files distributed through various peer-to-peer networks. The impact is particularly severe given the widespread use of these BitTorrent clients and the potential for attackers to leverage this vulnerability for broader exploitation campaigns.
Mitigation strategies for CVE-2008-4434 should focus on immediate software updates to versions that contain proper input validation and bounds checking mechanisms. System administrators and users should ensure that all BitTorrent clients are updated to the latest versions that address this specific vulnerability. Additionally, network-level defenses such as content filtering and torrent file scanning can provide additional protection layers, though these approaches are less reliable than proper software patching. The vulnerability demonstrates the importance of proper input validation in security-critical applications and aligns with ATT&CK tactics that emphasize privilege escalation and code execution through memory corruption vulnerabilities. Organizations should implement security awareness training to help users understand the risks associated with downloading torrent files from untrusted sources and maintain updated security tooling to detect and prevent exploitation attempts. Regular vulnerability assessments and penetration testing should include evaluation of client-side applications for similar buffer overflow conditions to prevent similar issues from arising in the future.