CVE-2017-12778 in qBittorrent
Summary
by MITRE
The UI Lock feature in qBittorrent version 3.3.15 is vulnerable to Authentication Bypass, which allows Attack to gain unauthorized access to qBittorrent functions by tampering the affected flag value of the config file at the C:\Users\<username>\Roaming\qBittorrent pathname. The attacker must change the value of the "locked" attribute to "false" within the "Locking" stanza.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 08/06/2024
The vulnerability identified as CVE-2017-12778 represents a critical authentication bypass flaw in qBittorrent version 3.3.15 that undermines the application's security model through improper configuration file handling. This issue specifically targets the UI Lock feature, which is designed to protect the graphical user interface from unauthorized access by requiring authentication before allowing access to core functions. The flaw manifests when an attacker manipulates the configuration file located in the Windows roaming profile directory at C:\Users\<username>\Roaming\qBittorrent, directly compromising the application's integrity controls. The vulnerability stems from the application's failure to properly validate the locked status flag during runtime, creating a path for unauthorized privilege escalation.
The technical implementation of this vulnerability follows a straightforward yet effective attack pattern that aligns with CWE-287, which addresses improper authentication mechanisms in software systems. The attacker exploits a simple configuration file modification by altering the "locked" attribute from its default value of "true" to "false" within the "Locking" stanza of the qBittorrent configuration file. This modification effectively disables the UI Lock protection mechanism without requiring any specialized credentials or advanced exploitation techniques. The flaw demonstrates poor input validation and insufficient access control checks, as the application fails to verify the integrity of the configuration file or re-validate the lock status during application initialization. The attack vector is particularly concerning because it requires no network connectivity or complex exploitation methods, relying solely on local file system manipulation.
The operational impact of this vulnerability extends beyond simple unauthorized access to encompass potential data compromise and system integrity violations. Once an attacker successfully bypasses the UI Lock, they gain access to all qBittorrent functions including torrent management, configuration settings, and potentially sensitive download data. This access could enable malicious actors to modify download queues, alter bandwidth settings, or even inject malicious torrents into the download process. The vulnerability particularly affects Windows environments where the roaming profile structure is utilized, making it relevant to enterprise users and organizations that rely on qBittorrent for file sharing operations. The attack scenario represents a classic privilege escalation vector that could lead to more significant security breaches if the compromised qBittorrent instance has access to sensitive network resources or shared drives.
Mitigation strategies for CVE-2017-12778 should focus on both immediate remediation and long-term security hardening measures. The most direct solution involves updating to a patched version of qBittorrent that properly validates the configuration file integrity and implements robust access control mechanisms. System administrators should also implement file system permissions controls to restrict write access to the qBittorrent configuration directory, particularly for non-administrative users. The implementation of file integrity monitoring solutions can help detect unauthorized modifications to critical configuration files. Additionally, users should be educated about the risks of running applications with elevated privileges and the importance of maintaining secure file system permissions. Organizations should consider implementing application whitelisting policies that restrict execution of unauthorized modifications to critical application components. This vulnerability highlights the importance of proper configuration management and access control validation in client-side applications, as outlined in the ATT&CK framework's privilege escalation techniques. The security implications underscore the need for comprehensive security testing of authentication mechanisms and proper validation of all user-controllable parameters within application configuration files.