CVE-2010-3357 in gnome-subtitles
Summary
by MITRE
gnome-subtitles 1.0 places a zero-length directory name in the LD_LIBRARY_PATH, which allows local users to gain privileges via a Trojan horse shared library in the current working directory.
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Analysis
by VulDB Data Team • 09/27/2021
The vulnerability identified as CVE-2010-3357 affects gnome-subtitles version 1.0 and represents a classic privilege escalation flaw stemming from improper library path handling. This issue occurs when the application processes the LD_LIBRARY_PATH environment variable by including a zero-length directory name, which creates an exploitable condition where local attackers can manipulate the dynamic linking process. The flaw resides in how the software manages library search paths, specifically when it encounters an empty directory component within the library path specification.
This vulnerability operates through a Trojan horse attack vector where an attacker places a malicious shared library in the current working directory from which gnome-subtitles is executed. When the application attempts to load required libraries, the zero-length directory component in LD_LIBRARY_PATH causes the system to search the current working directory first, before examining the standard library locations. This behavior violates the principle of least privilege and creates a path traversal vulnerability that can be exploited by local users. The flaw essentially allows an attacker to substitute legitimate system libraries with malicious versions simply by placing them in the working directory.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass potential system compromise and data exposure. A local attacker who can execute gnome-subtitles with elevated privileges or who can influence the application's execution context can gain unauthorized access to system resources. This vulnerability aligns with CWE-426 Untrusted Search Path and follows the ATT&CK technique T1068 Valid Accounts for privilege escalation. The exploit requires minimal prerequisites since it only necessitates the ability to place files in the working directory where the vulnerable application executes, making it particularly dangerous in multi-user environments.
Mitigation strategies for this vulnerability should focus on proper environment variable sanitization and library path management within the application. The most effective approach involves removing empty directory components from LD_LIBRARY_PATH before processing library searches, which prevents the unintended current directory traversal. Additionally, developers should implement secure coding practices that avoid relying on the current working directory for library loading and instead use explicit library paths or system-standard locations. System administrators should monitor for vulnerable applications and ensure proper file permissions are enforced to limit the ability of unprivileged users to place malicious libraries in execution directories. This vulnerability underscores the importance of adhering to security best practices for environment variable handling and demonstrates how seemingly minor implementation flaws can create significant security risks. The issue also highlights the necessity of proper privilege separation and the dangers of allowing applications to search untrusted directories during library loading operations.