CVE-2026-108772 in abstruse
Summary
by MITRE • 10/12/2026
A security vulnerability has been detected in bleenco abstruse up to 2.1.0. This issue affects the function filepath.Join of the file server/api/worker/download_cache.go of the component Cache Endpoint. Such manipulation of the argument File leads to path traversal. The attack can be launched remotely. The exploit has been disclosed publicly and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
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Analysis
by VulDB Data Team • 10/12/2026
The vulnerability identified within bleenco abstruse versions up to 2.1.0 represents a critical path traversal flaw located specifically within the Cache Endpoint component of the application architecture. This security issue stems from improper validation and sanitization practices employed by the filepath.Join function in the server/api/worker/download_cache.go file. When processing user-supplied input for the File argument, the system fails to adequately neutralize special elements such as dot-dot sequences or absolute path indicators before joining them with base directory paths. This lack of rigorous input validation allows an attacker to manipulate the constructed file path, effectively breaking out of the intended sandboxed directory structure and accessing arbitrary files on the underlying operating system filesystem.
From a technical perspective, this flaw is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory. The core mechanism involves the concatenation of user-controlled input with a base path without sufficient checks to ensure that the resulting absolute path remains within the expected directory boundaries. In many implementations, if the filepath.Join function is used incorrectly or followed by insufficient post-processing validation, an attacker can inject sequences like ../ which cause the file system resolution logic to traverse upwards in the directory hierarchy. This allows access to sensitive configuration files, source code, environment variables containing credentials, or other critical data that resides outside the designated cache or public directories. The vulnerability is particularly dangerous because it does not require authentication if the endpoint is publicly accessible, and even if restricted, it could be exploited by authenticated users with lower privileges to escalate their impact significantly.
The operational impact of this vulnerability is severe due to its remote exploitability. Since the attack can be launched remotely over a network connection, an adversary who discovers this flaw does not need physical access or local shell access to compromise the system integrity. The public disclosure and availability of exploits mean that automated scanning tools and malicious actors are actively targeting systems running affected versions. Successful exploitation could lead to unauthorized data exposure, where sensitive information is read from the server's file system. In more complex scenarios involving writable directories or specific service configurations, this path traversal could potentially serve as a precursor to remote code execution if an attacker can write shellcode into accessible locations and trigger its execution through other application features. The vendor's lack of response to early contact further exacerbates the risk landscape, leaving users without official patches or guidance for remediation during the window of exposure.
To mitigate this vulnerability, immediate action is required as no patch has been provided by the vendor. Administrators should implement strict input validation on all file path parameters before they are processed by system functions like filepath.Join. This includes rejecting any input containing relative path sequences such as .. or absolute paths that do not resolve within an allowed whitelist of directories. Additionally, deploying a Web Application Firewall with rules specifically designed to detect and block path traversal attempts can provide a layer of defense in depth while the application is updated. If possible, upgrading to a version where this issue has been resolved by the vendor should be prioritized once available. Until then, restricting network access to the Cache Endpoint API to trusted IP addresses only reduces the attack surface significantly. It is also advisable to run the service with minimal file system permissions, ensuring that even if path traversal occurs, the process lacks read or write access to critical system files outside its designated working directory.