CVE-2018-18207 in Virtualmin
Summary
by MITRE
Virtualmin 6.03 allows Frame Injection via the settings-editor_read.cgi file parameter.
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Analysis
by VulDB Data Team • 04/01/2020
Virtualmin 6.03 contains a frame injection vulnerability through the settings-editor_read.cgi file parameter that represents a critical security flaw in the web-based system management interface. This vulnerability falls under the CWE-79 category of Cross-Site Scripting (XSS) and specifically manifests as a frame injection attack vector that can be exploited by malicious actors to manipulate the browser's frame environment. The vulnerability arises from insufficient input validation and sanitization within the settings-editor_read.cgi component, which processes user-supplied parameters without proper security controls. Attackers can leverage this weakness by crafting malicious payloads that include iframe tags or other frame-related HTML elements in the parameter value, potentially leading to unauthorized frame manipulation within the victim's browser context.
The operational impact of this vulnerability extends beyond simple XSS exploitation, as frame injection can enable more sophisticated attack vectors including clickjacking, content spoofing, and potential privilege escalation within the Virtualmin administrative interface. When an authenticated user accesses a maliciously crafted URL containing the vulnerable parameter, the system fails to properly escape or validate the input before rendering it within the browser environment. This creates an opportunity for attackers to inject malicious frame content that can overlay legitimate interface elements, redirect users to malicious sites, or harvest credentials from the administrative session. The vulnerability affects the integrity of the web interface and can compromise the confidentiality and availability of system configurations managed through Virtualmin's administrative panel.
Security professionals should note that this vulnerability aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter and T1566.001 for Phishing, as attackers can use frame injection to create convincing phishing interfaces or execute malicious commands through compromised administrative sessions. The exploitation typically requires an authenticated user context, making social engineering or credential compromise prerequisites for successful attack execution. Organizations using Virtualmin 6.03 should implement immediate mitigations including input validation, parameter sanitization, and proper output encoding to prevent frame injection attacks. The recommended remediation involves updating to a patched version of Virtualmin where the settings-editor_read.cgi component properly validates and sanitizes all user inputs, implements Content Security Policy headers to restrict frame embedding, and enforces proper parameter validation within the web application framework. Additionally, network segmentation and monitoring solutions should be deployed to detect anomalous access patterns that might indicate exploitation attempts.