CVE-2023-27755 in go-bbs
Summary
by MITRE • 04/17/2023
go-bbs v1 was discovered to contain an arbitrary file download vulnerability via the component /api/v1/download.
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Analysis
by VulDB Data Team • 11/22/2025
The vulnerability identified as CVE-2023-27755 affects go-bbs v1, a web application that appears to be a bulletin board system or similar platform. This system exposes an API endpoint at /api/v1/download that suffers from an arbitrary file download flaw, representing a critical security weakness that could allow unauthorized access to sensitive system files. The vulnerability stems from insufficient input validation and access control mechanisms within the download component, enabling attackers to specify arbitrary file paths that should not be accessible through the public interface.
This arbitrary file download vulnerability falls under the category of CWE-552 which specifically addresses files that are too large to be processed or files that are improperly protected. The flaw allows an attacker to bypass normal access controls and potentially download any file that the web application process has read access to, including configuration files, database files, source code, or system files. The attack vector is particularly dangerous because it can be exploited through a simple HTTP request to the vulnerable endpoint without requiring authentication or elevated privileges. The lack of proper path validation means that attackers can manipulate the download component to retrieve files from the server's file system through relative path traversal or direct path specification.
The operational impact of this vulnerability is severe and multifaceted, as it provides attackers with the capability to extract sensitive data from the server environment. An attacker could potentially access database connection strings, API keys, cryptographic certificates, or application source code that would provide significant leverage for further exploitation. The vulnerability could also enable attackers to download system configuration files or log files that might contain additional attack vectors or sensitive information about the system architecture. This type of vulnerability directly relates to ATT&CK technique T1213 which involves data from information repositories and can lead to privilege escalation, lateral movement, or complete system compromise depending on what files are accessible through the download function.
Mitigation strategies should focus on implementing strict input validation and access control measures for the download endpoint. The system should validate all file paths against a whitelist of allowed directories and files, implement proper authentication checks, and ensure that the download component operates with minimal required privileges. Network segmentation and web application firewalls can provide additional protection layers to detect and block malicious requests targeting the vulnerable API endpoint. Regular security audits should be conducted to identify and remediate similar vulnerabilities across the application, and input sanitization should be implemented to prevent path traversal attacks. The vulnerability also highlights the importance of following secure coding practices and conducting thorough security testing of API endpoints before deployment, particularly those that handle file operations or system-level access. Organizations should consider implementing automated security scanning tools that can detect such vulnerabilities during the development lifecycle rather than discovering them post-deployment through security research or incident response activities.