CVE-2019-9976 in H660RM
Summary
by MITRE
The Boa server configuration on DASAN H660RM devices with firmware 1.03-0022 logs POST data to the /tmp/boa-temp file, which allows logged-in users to read the credentials of administration web interface users.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 05/24/2020
The CVE-2019-9976 vulnerability affects DASAN H660RM devices running firmware version 1.03-0022, specifically targeting the Boa web server implementation. This issue represents a critical security flaw in the device's web interface logging mechanism that exposes sensitive administrative credentials to authenticated users. The vulnerability stems from improper handling of POST data within the Boa server configuration, where user-submitted data is inadvertently written to temporary files without adequate access controls or sanitization measures.
The technical exploitation of this vulnerability occurs through the Boa web server's logging functionality that writes POST request data to the /tmp/boa-temp file location. This file is created in a world-readable temporary directory, allowing any logged-in user with access to the device to read the contents of the temporary file. The flaw demonstrates poor privilege separation and inadequate temporary file management practices, as the server configuration fails to properly secure sensitive data during processing. This represents a clear violation of security best practices and demonstrates a failure in implementing proper access controls for temporary storage mechanisms.
The operational impact of this vulnerability is severe as it enables authenticated users to escalate their privileges and gain unauthorized access to administrative web interface credentials. Attackers who have already established a login session on the device can leverage this vulnerability to extract administrative passwords, potentially leading to complete system compromise. The exposure of administrative credentials undermines the entire security model of the device, as it provides attackers with the means to bypass normal authentication mechanisms and gain full administrative control over the network infrastructure. This vulnerability directly impacts the confidentiality and integrity aspects of the device's security posture.
Mitigation strategies for CVE-2019-9976 should focus on immediate remediation through firmware updates provided by DASAN, as well as temporary workarounds such as restricting access to the /tmp/boa-temp file and implementing proper file permissions. Organizations should conduct comprehensive vulnerability assessments of all DASAN H660RM devices in their network to identify affected systems and prioritize remediation efforts. The vulnerability aligns with CWE-276, which addresses improper file permissions, and reflects ATT&CK technique T1078 for valid accounts and T1566 for credential access through web application vulnerabilities. Network segmentation and monitoring for unusual file access patterns in temporary directories should also be implemented to detect potential exploitation attempts.