CVE-2009-3894 in dstat
Summary
by MITRE
Multiple untrusted search path vulnerabilities in dstat before 0.7.0 allow local users to gain privileges via a Trojan horse Python module in (1) the current working directory or (2) a certain subdirectory of the current working directory.
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Analysis
by VulDB Data Team • 02/10/2025
The vulnerability identified as CVE-2009-3894 represents a critical privilege escalation issue affecting dstat versions prior to 0.7.0. This vulnerability falls under the category of untrusted search path exploitation, a well-documented weakness that has been classified under CWE-426 by the CWE standard. The flaw specifically targets the Python module loading mechanism within dstat, creating an environment where malicious actors can manipulate the execution flow by placing specially crafted Python modules in strategically located directories.
The technical implementation of this vulnerability exploits the way dstat resolves Python module paths during execution. When dstat operates, it searches for required Python modules in a specific order that includes the current working directory and certain subdirectories. This search order creates an opportunity for privilege escalation because local users can place malicious Python modules in these directories, which will then be loaded and executed with elevated privileges. The vulnerability specifically affects the module loading process where dstat does not properly validate or sanitize the module paths, allowing arbitrary code execution through the Trojan horse module technique.
The operational impact of this vulnerability extends beyond simple privilege escalation as it can be exploited in various attack scenarios. An attacker with local access can leverage this weakness to execute arbitrary code with the privileges of the dstat process, which typically runs with elevated permissions. This creates a significant security risk particularly in environments where dstat is used for system monitoring and where local users might have access to the system. The attack vector is particularly dangerous because it requires minimal privileges to exploit and can be executed without requiring network access or complex attack chains.
From an ATT&CK framework perspective, this vulnerability maps to the privilege escalation technique where adversaries use weaknesses in software to gain higher privileges than initially granted. The technique leverages the legitimate module loading functionality of the application to achieve malicious objectives, making detection more challenging as the malicious activity appears to be normal application behavior. The vulnerability also aligns with the defense evasion category since it can be used to establish persistent access or hide malicious activities within normal system operations.
The recommended mitigation strategy involves upgrading to dstat version 0.7.0 or later, which addresses this specific vulnerability through proper module path validation and sanitization. Additionally, system administrators should implement strict directory permissions and monitoring to prevent unauthorized module placement in critical directories. The principle of least privilege should be enforced by limiting local user access to directories where dstat executes, and regular security audits should verify that no malicious modules exist in the search paths. Organizations should also consider implementing application whitelisting policies that restrict which Python modules can be loaded by dstat, providing an additional layer of protection against similar vulnerabilities in other applications.