CVE-2008-4486 in Yerba
Summary
by MITRE
Directory traversal vulnerability in index.php in SAC.php (SACphp), as used in Yerba 6.3 and earlier, allows remote attackers to include and execute arbitrary local files via a .. (dot dot) in the mod parameter.
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Analysis
by VulDB Data Team • 11/06/2024
The vulnerability identified as CVE-2008-4486 represents a critical directory traversal flaw within the SACphp component of Yerba versions 6.3 and earlier. This issue manifests in the index.php file where the mod parameter fails to properly validate input, creating an exploitable condition that allows remote attackers to manipulate file inclusion paths. The vulnerability stems from inadequate sanitization of user-supplied input, specifically allowing attackers to append directory traversal sequences such as .. to navigate outside the intended directory structure. This weakness enables unauthorized access to local files that should remain restricted, potentially exposing sensitive system resources including configuration files, database credentials, or other privileged data. The flaw exists at the application level where user input directly influences file system operations without proper access control mechanisms.
The technical exploitation of this vulnerability follows a well-established pattern that aligns with CWE-22, which categorizes improper limitation of a pathname to a restricted directory. Attackers can craft malicious URLs containing the .. sequence within the mod parameter to traverse directories and access files outside the web root or intended application boundaries. When the application processes such input, it performs file inclusion operations without validating whether the requested path remains within acceptable limits. This creates a path traversal condition where arbitrary local files can be included and executed, potentially leading to remote code execution depending on the system configuration and file permissions. The vulnerability demonstrates a classic lack of input validation and output encoding that violates fundamental security principles for preventing unauthorized file access.
The operational impact of CVE-2008-4486 extends beyond simple information disclosure, as it can enable complete system compromise when combined with other attack vectors. Remote attackers can leverage this vulnerability to access sensitive configuration files that may contain database passwords, API keys, or system credentials. The ability to execute arbitrary local files opens pathways for privilege escalation and persistent access to compromised systems. Organizations running affected versions of Yerba face significant risk of data breaches, system infiltration, and potential lateral movement within their network infrastructure. The vulnerability affects web applications that rely on dynamic file inclusion based on user input, making it particularly dangerous in environments where multiple applications share common file systems or where file permissions are not properly enforced.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term architectural improvements to prevent similar issues. The primary fix involves implementing strict input validation and sanitization for all parameters that influence file system operations, particularly those used in include or require statements. Developers should employ whitelisting approaches for valid module names or implement proper path validation that prevents traversal sequences from being processed. Organizations should also consider implementing proper access controls and least privilege principles for file system operations, ensuring that applications cannot access files outside their designated directories. Additionally, regular security assessments and code reviews should be conducted to identify and remediate similar vulnerabilities in other components of the application stack. The vulnerability highlights the importance of following secure coding practices and adhering to ATT&CK framework concepts related to privilege escalation and persistence mechanisms that attackers may leverage through such path traversal exploits.