CVE-2005-1707 in webapp-config
Summary
by MITRE
The fn_show_postinst function in Gentoo webapp-config before 1.10-r14 allows local users to overwrite arbitrary files via a symlink attack on the postinst.txt temporary file.
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Analysis
by VulDB Data Team • 12/29/2024
The vulnerability described in CVE-2005-1707 represents a critical security flaw in the Gentoo Linux distribution's webapp-config utility, specifically within the fn_show_postinst function. This issue affects versions prior to 1.10-r14 and demonstrates a classic symlink attack pattern that enables local privilege escalation through file overwrite operations. The vulnerability arises from improper handling of temporary files during the package installation process, creating an exploitable race condition that can be leveraged by malicious local users to gain elevated privileges.
The technical flaw stems from the function's failure to properly validate or secure temporary file creation processes. When webapp-config executes the fn_show_postinst function, it creates a temporary file named postinst.txt without adequate security measures to prevent symbolic link attacks. Local users can exploit this by creating malicious symbolic links that point to sensitive system files, such as configuration files or binaries, before the legitimate installation process completes. This race condition allows attackers to overwrite critical files with malicious content, potentially leading to privilege escalation or system compromise. The vulnerability aligns with CWE-377, which addresses insecure temporary file creation practices, and demonstrates the dangers of inadequate file handling security measures in system utilities.
The operational impact of this vulnerability extends beyond simple file overwrites, as it provides attackers with a potential pathway for privilege escalation within Gentoo systems. Attackers can leverage this flaw to modify critical system files, inject malicious code into installed applications, or manipulate system configurations to maintain persistent access. The vulnerability affects all local users on affected systems, making it particularly dangerous in multi-user environments where users may have varying privilege levels. The attack requires local access but can be particularly damaging in scenarios where users have the ability to install packages or execute system utilities, as the exploitation can occur during routine package management operations. This vulnerability has implications for system integrity and can undermine the security model of Gentoo installations.
Mitigation strategies for this vulnerability require immediate patching of affected webapp-config installations to version 1.10-r14 or later, which addresses the symlink attack vulnerability through proper temporary file handling. System administrators should also implement additional security controls such as restricting write permissions on critical directories, monitoring for suspicious symbolic link creation activities, and ensuring proper file ownership and permissions are maintained. The remediation process should include verification that all temporary file operations use secure creation methods, including the use of secure temporary file functions and proper file descriptor management. Organizations should also consider implementing automated scanning tools to identify systems running vulnerable versions and establish monitoring procedures to detect potential exploitation attempts. This vulnerability highlights the importance of following secure coding practices and proper temporary file management as outlined in industry standards such as the OWASP Secure Coding Practices and NIST guidelines for secure software development.