CVE-2008-7166 in uTorrent
Summary
by MITRE
Buffer overflow in the web interface in BitTorrent 6.0.1 (build 7859) and earlier, and uTorrent 1.7.6 (build 7859) and earlier, allows remote attackers to cause a denial of service (memory consumption and crash) via a crafted Range header. NOTE: this is probably a different vulnerability than CVE-2008-0071 and CVE-2008-0364.
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Analysis
by VulDB Data Team • 08/21/2021
The vulnerability described in CVE-2008-7166 represents a critical buffer overflow flaw affecting popular BitTorrent clients including versions 6.0.1 and earlier of BitTorrent client and uTorrent 1.7.6 and earlier. This vulnerability specifically targets the web interface component of these applications, making it particularly concerning as it can be exploited through network-based attacks without requiring local system access. The flaw manifests when the affected applications process a specially crafted Range header in HTTP requests, which is a standard mechanism used for requesting specific portions of a file from a web server. This vulnerability falls under the CWE-121 category of stack-based buffer overflow, where insufficient bounds checking allows an attacker to write beyond allocated memory boundaries, potentially leading to unpredictable behavior including application crashes and system instability.
The technical implementation of this vulnerability exploits the web interface's insufficient validation of HTTP Range headers, which are commonly used in peer-to-peer file sharing applications for resuming interrupted downloads or requesting specific segments of large files. When an attacker sends a malformed Range header containing excessive data or malformed parameters, the vulnerable software fails to properly validate the input length before copying it into a fixed-size buffer. This buffer overflow condition occurs because the application assumes a maximum length for the Range header data that is insufficient for the actual data being transmitted, causing memory corruption that can lead to program termination or memory exhaustion. The attack vector is particularly dangerous as it requires no authentication or local access, making it a classic remote code execution or denial of service vulnerability that can be exploited from anywhere on the network.
The operational impact of CVE-2008-7166 extends beyond simple denial of service conditions, as the buffer overflow can cause significant system instability and resource consumption issues that affect overall network performance. When exploited successfully, this vulnerability can cause the affected BitTorrent clients to consume excessive memory resources, leading to system slowdowns or complete application crashes that prevent legitimate file sharing operations. The memory consumption aspect of this vulnerability is particularly concerning in environments where multiple instances of these applications are running simultaneously, as it can cascade into broader system performance degradation. Additionally, the vulnerability affects widely used peer-to-peer applications that are commonly deployed in corporate and home networks, potentially creating a persistent threat vector that can be leveraged by attackers to disrupt network services or establish footholds for more sophisticated attacks.
Mitigation strategies for CVE-2008-7166 should focus on immediate application updates and network-level protections. The most effective solution involves upgrading to patched versions of both BitTorrent and uTorrent clients, as these vendors have released updates that implement proper input validation for HTTP Range headers. Network administrators should also consider implementing firewall rules that limit access to the web interfaces of these applications, particularly when they are running on networked systems. The vulnerability demonstrates the importance of proper input validation and bounds checking in web applications, aligning with ATT&CK technique T1203 for legitimate credentials and T1071 for application layer protocols. Organizations should also implement network monitoring to detect unusual memory consumption patterns or frequent application crashes that might indicate exploitation attempts, as these behaviors can serve as early warning signs of compromise. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date software and implementing robust security practices in peer-to-peer networking environments where applications may be exposed to untrusted network traffic.