CVE-2005-4443 in gauche
Summary
by MITRE
untrusted search path vulnerability in gauche before 0.8.6-r1 on gentoo linux allows local users in the portage group to gain privileges via a malicious shared object in the portage temporary build directory which is part of the runpath.
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Analysis
by VulDB Data Team • 06/12/2019
The vulnerability described in CVE-2005-4443 represents a critical untrusted search path issue affecting the gauche scripting language version 0.8.5 and earlier on Gentoo Linux systems. This flaw specifically targets the portage package management system's temporary build directory, creating a privilege escalation vector for local attackers who are members of the portage group. The vulnerability stems from improper handling of dynamic library loading paths during the build process, where the system inadvertently includes the portage temporary directory in the runtime library search path. This configuration allows malicious actors to place specially crafted shared objects within the build directory, which will then be loaded by legitimate build processes, enabling unauthorized privilege elevation.
The technical implementation of this vulnerability aligns with CWE-426, which describes untrusted search path vulnerabilities where applications use paths that can be manipulated by attackers. The flaw occurs because the gauche build environment does not properly sanitize or validate the library search paths, particularly when processing packages that require compilation. When portage executes build processes in the temporary directory, it inherits the system's default library search behavior, which includes the temporary directory in the runpath. This creates a scenario where any shared object placed in the temporary directory can be loaded by programs that are executed with elevated privileges during the package building process. The vulnerability operates under the principle that the system trusts the contents of directories that are part of its library search path without proper verification of their integrity.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with a method to execute arbitrary code with the privileges of the portage group members, which typically have elevated system access. This allows for potential system compromise, data exfiltration, or further attack progression within the compromised environment. The vulnerability is particularly concerning in multi-user environments where portage group membership might be granted to users who should not have such elevated privileges. Attackers can leverage this weakness to gain persistent access, modify system packages, or establish backdoors within the system. The attack requires local access and membership in the portage group, but the privilege escalation potential makes it a significant security concern for system administrators who manage package installations and updates.
Mitigation strategies for this vulnerability include immediate patching of the gauche package to version 0.8.6-r1 or later, which addresses the untrusted search path issue by properly sanitizing library search paths during build processes. System administrators should also implement stricter access controls for the portage temporary directories, ensuring that only authorized users can write to these locations. The principle of least privilege should be enforced by limiting portage group membership to only those users who absolutely require package management capabilities. Additionally, implementing proper file system permissions and using secure temporary directory configurations can prevent unauthorized code injection. Organizations should also consider implementing monitoring solutions that can detect suspicious activity in package build directories, as outlined in the attack techniques described in the MITRE ATT&CK framework under privilege escalation tactics. Regular security audits and vulnerability assessments should be conducted to identify similar issues in other system components, particularly those that handle dynamic library loading and package management processes.