CVE-2026-108902 in pH7Builder
Summary
by MITRE • 10/11/2026
pH7Builder (pH7 Social Dating CMS) before 18.5.0 contains a path traversal vulnerability in the picture module deletePhoto() action that allows authenticated members to delete arbitrary files. Attackers can supply ../ sequences in the POST picture_link parameter to remove other members' photos or configuration and cache files, causing content loss and denial of service.
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Analysis
by VulDB Data Team • 10/11/2026
The pH7Builder Content Management System, specifically versions prior to 18.5.0, contains a critical path traversal vulnerability within its photo management module. This flaw resides in the deletePhoto action handler, which processes user input from the POST parameter named picture_link without adequate sanitization or validation of directory traversal sequences. The vulnerability allows authenticated users to manipulate file system paths by injecting relative parent directory references, commonly known as dot-dot-slash sequences, into the request payload. Because the application fails to properly canonicalize these inputs before passing them to underlying operating system functions for deletion operations, an attacker can redirect the delete command away from the intended photo storage directories and target arbitrary files elsewhere on the server file system.
From a technical perspective, this vulnerability is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory. The root cause lies in insufficient input validation where the application trusts user-supplied path components without verifying that they remain within the expected boundary of the photo directory structure. By appending sequences such as ../ to the picture_link parameter, an attacker can traverse up multiple levels of the directory hierarchy. This capability effectively bypasses any logical access controls designed to restrict file operations to specific subdirectories, granting the authenticated user elevated privileges equivalent to those required for direct file system manipulation within the context of the web application process.
The operational impact of this vulnerability is severe and multifaceted. Primarily, it enables malicious actors to delete arbitrary files belonging to other members, leading to significant data loss and erosion of trust among the platform's user base. Beyond targeted content destruction, attackers can exploit this flaw to remove critical configuration files, cache data, or even sensitive system files if permissions allow. Such actions result in a denial of service condition for legitimate users who may find their profiles corrupted or inaccessible due to missing assets. Furthermore, depending on the specific file types and locations accessible through traversal, there is potential for further exploitation chains that could compromise server integrity or facilitate remote code execution if combined with other vulnerabilities like insecure deserialization or template injection in subsequent steps.
In terms of threat modeling, this vulnerability aligns with MITRE ATT&CK techniques related to Impact via Data Destruction and potentially Initial Access if the authentication mechanism itself is weak, though it primarily falls under lateral movement or privilege escalation within the application context once authenticated. The attack vector requires valid credentials, meaning it targets insider threats or compromised accounts rather than unauthenticated external attackers directly. However, given that many social dating platforms have large user bases with varying levels of security awareness, the risk of credential compromise is non-trivial, making this vulnerability a high-priority target for exploitation campaigns aimed at disrupting service integrity and causing reputational damage to the platform operator.
To mitigate this vulnerability, immediate patching to version 18.5.0 or later is strongly recommended as it addresses the underlying input validation flaws in the picture module. For environments where upgrading is not immediately feasible, defense-in-depth strategies should be implemented at the web server level using strict allow-lists for file paths and disabling directory traversal characters in request parameters via WAF rules. Additionally, developers must enforce canonicalization of all file path inputs before processing them to ensure they resolve within expected directories. Implementing robust access control checks that verify the resolved absolute path against a whitelist of allowed base directories is essential. Regular security audits focusing on file system operations and input validation patterns across the CMS codebase are also advised to prevent similar issues in other modules.