CVE-2005-3156 in EasyGuppy
Summary
by MITRE
Directory traversal vulnerability in printfaq.php in EasyGuppy (Guppy for Windows) 4.5.4 and 4.5.5 allows remote attackers to read arbitrary files via ".." sequences in the pg parameter, which is cleansed for XSS but not directory traversal.
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Analysis
by VulDB Data Team • 07/06/2021
The vulnerability identified as CVE-2005-3156 represents a critical directory traversal flaw in EasyGuppy version 4.5.4 and 4.5.5, specifically within the printfaq.php component. This issue arises from insufficient input validation mechanisms that fail to properly sanitize user-supplied data, creating an exploitable condition that allows remote attackers to access arbitrary files on the affected system. The vulnerability manifests when the pg parameter undergoes XSS cleansing but remains vulnerable to directory traversal attacks through the use of ".." sequences.
The technical exploitation of this vulnerability occurs because the application processes the pg parameter without adequately validating or filtering directory traversal sequences. While the software implements measures to prevent cross-site scripting attacks by cleaning the pg parameter, these protective measures are insufficient against directory traversal attempts. Attackers can manipulate the pg parameter to navigate through the file system hierarchy, potentially accessing sensitive files such as configuration data, database credentials, or other system files that should remain protected from unauthorized access. This flaw directly maps to CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as directory traversal or path traversal attacks.
The operational impact of this vulnerability extends beyond simple information disclosure, as successful exploitation could lead to complete system compromise. An attacker with remote access capabilities could potentially read system configuration files, application source code, or sensitive data stored in the application's directory structure. The vulnerability affects not only the immediate confidentiality of data but also creates potential entry points for further exploitation, as access to system files may reveal additional attack vectors or sensitive information that could be leveraged for privilege escalation or lateral movement within the network. This aligns with ATT&CK technique T1083, which describes discovering files and directories, and T1005, which covers data from local system.
Mitigation strategies for CVE-2005-3156 must address both the immediate vulnerability and implement comprehensive input validation controls. Organizations should immediately apply patches or updates provided by the vendor to resolve the directory traversal flaw in EasyGuppy. Additionally, implementing proper input validation techniques such as whitelisting allowed values, canonicalizing file paths, and employing absolute path resolution methods can prevent similar vulnerabilities. Network segmentation and access controls should be implemented to limit the potential impact of exploitation, while monitoring systems should be configured to detect anomalous file access patterns that may indicate exploitation attempts. Security configurations should enforce strict file access controls and disable unnecessary file access capabilities within the application's directory structure to minimize the attack surface.