CVE-2019-13033 in Lynis
Summary
by MITRE
In CISOfy Lynis 2.x through 2.7.5, the license key can be obtained by looking at the process list when a data upload is being performed. This license can be used to upload data to a central Lynis server. Although no data can be extracted by knowing the license key, it may be possible to upload the data of additional scans.
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Analysis
by VulDB Data Team • 10/25/2020
The vulnerability identified as CVE-2019-13033 affects CISOfy Lynis versions 2.x through 2.7.5, representing a critical information disclosure weakness that exposes sensitive authentication credentials through process monitoring techniques. This flaw resides in the software's handling of license keys during data upload operations, where the cryptographic token required for authentication is inadvertently exposed in the process list. The vulnerability operates under the principle of information exposure through process inspection, which aligns with CWE-200, and specifically manifests as a credential exposure issue during network communication phases. The license key serves as the primary authentication mechanism for uploading scan results to centralized Lynis servers, making this exposure particularly concerning for organizations relying on the tool for security compliance and vulnerability management.
The technical implementation of this vulnerability occurs when Lynis performs data upload operations, during which the license key becomes visible in the process list accessible through standard system monitoring tools such as ps, top, or htop commands. This exposure happens because the application fails to properly sanitize or obfuscate the license key during the upload process, allowing any user with access to the system's process information to extract the authentication token. The vulnerability does not permit data extraction or direct system compromise, but rather enables unauthorized data injection into the central Lynis server infrastructure. This behavior represents a violation of the principle of least privilege and demonstrates poor input validation and credential handling practices, which can be categorized under ATT&CK technique T1078 for Valid Accounts and T1566 for Phishing.
The operational impact of this vulnerability extends beyond simple credential exposure, as it enables potential attackers to perform unauthorized data uploads to the centralized Lynis server, potentially leading to false positive or negative security assessments. Organizations using Lynis for compliance monitoring and security auditing may face compromised integrity of their security data, as malicious actors could upload fabricated scan results to manipulate security dashboards and reporting mechanisms. The vulnerability creates a pathway for attackers to manipulate security metrics and potentially evade detection by uploading false scan results that appear legitimate to the central server. This type of attack can significantly impact security posture assessments and compliance reporting, particularly in regulated environments where accurate security data is crucial for audit purposes.
Mitigation strategies for CVE-2019-13033 should focus on immediate software updates to versions that address the credential exposure issue, as well as implementing process monitoring and access controls to limit visibility of sensitive information. Organizations should deploy process isolation techniques and ensure that license keys are handled through secure channels that do not expose them in process lists. The implementation of proper credential management practices, including the use of temporary tokens or session-based authentication, would prevent this type of exposure. Additionally, network segmentation and access controls should be implemented to restrict which systems can perform data uploads to the central Lynis server, reducing the attack surface and limiting the potential impact of credential exposure. System administrators should also consider implementing monitoring for unusual data upload patterns and establish procedures for regular credential rotation to minimize the window of opportunity for exploitation.