CVE-2025-57231 in Docmost
Summary
by MITRE • 09/11/2026
Path Traversal in avatar attachments in Docmost v0.21.0 allows an unauthenticated malicious actor to disclose local files via a POST Request in a public url.
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Analysis
by VulDB Data Team • 09/11/2026
The vulnerability identified as CVE-2024-38695 represents a critical path traversal flaw within the avatar attachment handling mechanism of Docmost version 0.21.0 and potentially earlier versions. This security defect allows an unauthenticated attacker to exploit improper input validation in the file upload functionality, specifically targeting the POST request endpoint used for processing avatar images. The core technical issue stems from the application's failure to adequately sanitize or canonicalize user-supplied filenames before using them to construct local filesystem paths. By injecting directory traversal sequences such as dot-dot-slash into the filename parameter during a POST request, an attacker can manipulate the file system navigation logic. This manipulation enables the reading of arbitrary files located on the server hosting the Docmost instance, effectively bypassing intended access controls that restrict users to their own profile data or public assets.
From a technical perspective, this vulnerability aligns with CWE-22: Improper Limitation of a Pathname to a Restricted Directory. The application likely concatenates user input directly into a base directory path without performing sufficient checks to ensure the resulting resolved path remains within the intended upload directory. When the server processes the POST request containing the malicious filename, it resolves the traversal characters against the file system root or the specific upload folder, allowing access to files outside of this restricted scope. Since the vulnerability is accessible via a public URL and requires no authentication, the attack surface is significantly expanded. An attacker does not need valid credentials or prior interaction with the application beyond knowing the endpoint structure, making it highly exploitable in internet-facing deployments.
The operational impact of this path traversal vulnerability extends far beyond simple file disclosure. By reading sensitive configuration files such as database connection strings, environment variables containing API keys and secrets, or internal system logs, an attacker can gain deep insights into the infrastructure's architecture and security posture. This information is often a precursor to more severe attacks, including remote code execution if executable scripts are accessible, or credential stuffing if password hashes are exposed. Furthermore, in cloud environments where instance metadata services are available on local loopback interfaces, path traversal vulnerabilities have historically been leveraged to access these endpoints by reading specific configuration files that reveal internal routing rules or proxy settings. The ability to read arbitrary files compromises the confidentiality of the entire system and can lead to a complete compromise of data integrity and availability if critical system files are overwritten or deleted in subsequent exploitation steps.
This vulnerability is also relevant to MITRE ATT&CK technique T1083: File and Directory Discovery, as it facilitates the enumeration and access of sensitive information on the host system without triggering typical authentication mechanisms. The lack of authentication requirement places this flaw in a high-risk category for automated scanning tools and opportunistic attackers who routinely probe web applications for common misconfigurations like path traversal. Organizations running Docmost must recognize that even unauthenticated endpoints require rigorous input validation, particularly when handling file uploads which are a frequent source of security defects due to the complexity of filename parsing across different operating systems and web server configurations.
To mitigate this vulnerability, immediate action is required by upgrading to a patched version of Docmost where the developers have implemented proper path canonicalization and strict allow-listing for allowed characters in filenames. In the interim, if an upgrade is not immediately feasible, network-level controls such as Web Application Firewalls can be configured to detect and block HTTP POST requests containing directory traversal sequences like dot-dot-slash or encoded variations thereof within filename parameters. Additionally, implementing principle of least privilege on the server account running the Docmost application ensures that even if file disclosure occurs, the attacker cannot access sensitive system files outside the web root or user directories. Regular security audits focusing on input validation for all file handling operations are essential to prevent similar defects in future development cycles and maintain a robust defense-in-depth posture against path traversal attacks.