CVE-2007-1799 in KTorrent
Summary
by MITRE
Directory traversal vulnerability in torrent.cpp in KTorrent before 2.1.3 only checks for the ".." string, which allows remote attackers to overwrite arbitrary files via modified ".." sequences in a torrent filename, as demonstrated by "../" sequences, due to an incomplete fix for CVE-2007-1384.
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Analysis
by VulDB Data Team • 07/18/2019
The vulnerability described in CVE-2007-1799 represents a directory traversal flaw in KTorrent version 2.1.2 and earlier, specifically within the torrent.cpp component responsible for handling torrent file processing. This security weakness stems from an inadequate implementation of file path validation mechanisms that were previously addressed in CVE-2007-1384 but not fully resolved. The core issue manifests when KTorrent processes torrent files containing specially crafted filenames that exploit the incomplete filtering logic designed to prevent directory traversal attacks.
The technical flaw occurs because KTorrent's implementation only examines and blocks direct occurrences of the ".." string within torrent filenames, failing to account for various obfuscation techniques that attackers can employ to bypass this protection mechanism. Attackers can construct malicious torrent files containing sequences such as "../" or other variations that, when processed by the vulnerable software, can result in the creation or modification of files outside the intended directory structure. This incomplete filtering approach creates a pathway for remote attackers to execute arbitrary file operations on the target system, potentially leading to unauthorized file overwrites, data corruption, or even system compromise.
The operational impact of this vulnerability extends beyond simple file manipulation, as it can enable attackers to target critical system files, configuration data, or user documents stored on the affected system. When exploited, the vulnerability allows remote code execution capabilities through file overwrites, particularly if the affected KTorrent process has sufficient privileges to modify system-critical files. This represents a significant security risk for users who may unknowingly download and process malicious torrent files, potentially leading to persistent compromise of their systems and unauthorized access to sensitive data. The vulnerability is particularly concerning in environments where torrent clients are used for legitimate file sharing but may inadvertently process compromised content.
Security practitioners should implement immediate mitigations including upgrading to KTorrent version 2.1.3 or later, which contains the proper fix for this vulnerability. The remediation approach should also include network-level controls such as implementing proxy filtering for torrent files and monitoring for suspicious file patterns in downloaded content. Organizations should also consider implementing least privilege principles for torrent client processes and conducting regular security assessments of file processing components. From an ATT&CK framework perspective, this vulnerability maps to techniques involving directory traversal and privilege escalation, while CWE classification places it under CWE-22 for Improper Limitation of a Pathname to a Restricted Directory, highlighting the fundamental flaw in path validation mechanisms. The vulnerability underscores the importance of comprehensive input validation and the need for robust security measures that account for various obfuscation techniques attackers may employ to bypass protection mechanisms.