CVE-2026-110666 in sar2html
Summary
by MITRE • 10/14/2026
A vulnerability was identified in cemtan sar2html 4.0.0. Affected is the function updateDb of the file sar2html.py of the component File Upload. The manipulation leads to path traversal. Remote exploitation of the attack is possible. The project was informed of the problem early through an issue report but has not responded yet.
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Analysis
by VulDB Data Team • 10/15/2026
The identified vulnerability in cemtan sar2html version 4.0.0 represents a critical security flaw within the application's file upload functionality, specifically located in the updateDb function found in the sar2html.py module. This component is responsible for processing uploaded files and updating associated database records to reflect system performance metrics or historical data. The core technical issue stems from insufficient validation of user-supplied input during the file handling process. When a remote attacker interacts with this endpoint, they can manipulate the filename or path parameters provided in the upload request. Because the application fails to properly sanitize these inputs before using them for filesystem operations, it allows an adversary to inject directory traversal sequences such as dot-dot-slash characters into the target path. This lack of input validation enables the manipulation of file system access controls, leading directly to a Path Traversal vulnerability where the attacker can dictate which files on the underlying operating system are read or overwritten by the application.
From a technical perspective, this flaw aligns with CWE-22 Improper Limitation of a Pathname to a Restricted Directory and CWE-94 Improper Control of Generation of Code (Path Traversal). The vulnerability arises because the updateDb function likely concatenates user-controlled strings directly into file paths without verifying that the resulting path remains within an expected, safe directory structure. In many web applications handling system administration data like sar2html, which processes System Activity Report files, there is often a trust assumption regarding the integrity of uploaded filenames. However, this assumption is exploited by attackers who craft malicious payloads designed to escape the intended upload or temporary directories. By navigating up the directory tree using traversal sequences, an attacker can access sensitive configuration files, source code, or other critical system resources that are not meant to be publicly accessible through the web interface.
The operational impact of this vulnerability is severe due to its remote exploitability and potential for arbitrary file read or write operations. Since the attack vector is network-based, a remote unauthenticated attacker can potentially exfiltrate sensitive data from the server hosting sar2html. This could include database credentials stored in configuration files, private keys, or internal system logs that reveal architectural details of the environment. Furthermore, if the application permits file writes through this mechanism, an attacker might overwrite critical scripts or binaries, leading to Remote Code Execution (RCE). In the context of ATT&CK framework tactics, this vulnerability facilitates Initial Access and potentially Lateral Movement by allowing attackers to pivot from a web server compromise into deeper system layers. The ability to read arbitrary files can also aid in reconnaissance, helping adversaries map out the internal network structure and identify further targets for exploitation.
The fact that the project maintainers have been notified via an issue report but have not yet responded highlights a significant risk regarding supply chain security and patch availability. Organizations relying on this software must assume they are exposed until official patches or workarounds are released by the vendor. In such scenarios, defensive measures become paramount to mitigate the immediate threat landscape. Administrators should implement strict input validation at the application layer if source code access is available, ensuring that all file paths are canonicalized and checked against a whitelist of allowed directories before processing. Additionally, deploying Web Application Firewalls with rules specifically tuned for path traversal patterns can provide an additional layer of defense by blocking requests containing suspicious directory navigation sequences. It is also advisable to restrict the permissions of the user account running sar2html so that even if exploitation occurs, the attacker's ability to access sensitive system files is limited by operating system-level access controls. Regular monitoring of application logs for unusual file access patterns can help detect attempted exploits in real-time, allowing security teams to respond before significant damage is incurred.