CVE-2012-4893 in Webmin
Summary
by MITRE
Multiple cross-site request forgery (CSRF) vulnerabilities in file/show.cgi in Webmin 1.590 and earlier allow remote attackers to hijack the authentication of privileged users for requests that (1) read files or execute (2) tar, (3) zip, or (4) gzip commands, a different issue than CVE-2012-2982.
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Analysis
by VulDB Data Team • 08/11/2024
The CVE-2012-4893 vulnerability represents a critical cross-site request forgery flaw discovered in Webmin version 1.590 and earlier, specifically within the file/show.cgi component of the web-based system administration tool. This vulnerability enables remote attackers to exploit the authentication mechanisms of privileged users by crafting malicious requests that appear to originate from legitimate administrative sessions. The flaw resides in the insufficient validation of request origins and lack of proper anti-CSRF token implementation in the file management functionality, creating a pathway for unauthorized privilege escalation and system compromise.
The technical implementation of this vulnerability stems from the absence of robust CSRF protection measures in the file/show.cgi script which handles file operations within the Webmin interface. When privileged users navigate to maliciously crafted web pages or click on compromised links, the browser automatically submits requests to the Webmin server without requiring additional authentication. The vulnerability specifically affects four distinct operations: file reading, tar command execution, zip command execution, and gzip command execution, all of which can be leveraged to perform unauthorized administrative actions. This flaw operates under CWE-352, which categorizes cross-site request forgery vulnerabilities as a fundamental web application security weakness, where the application fails to validate that requests originate from legitimate sources.
The operational impact of this vulnerability is severe and multifaceted, as it allows attackers to execute arbitrary commands on the target system with the privileges of authenticated users. An attacker could potentially read sensitive system files, extract archives, compress data, or execute compression utilities to gain unauthorized access to system resources. The vulnerability's scope extends beyond simple data theft to include full system compromise, as the ability to execute tar, zip, and gzip commands can be leveraged to manipulate system files and potentially escalate privileges. This issue is distinct from CVE-2012-2982, which addressed different aspects of Webmin's security model, making CVE-2012-4893 a unique and particularly dangerous vulnerability in the context of web-based system administration tools.
Mitigation strategies for this vulnerability require immediate patching of affected Webmin installations to version 1.591 or later, where the CSRF protection mechanisms have been properly implemented. Organizations should also implement additional defensive measures including network segmentation, web application firewalls, and monitoring for suspicious administrative activities. The implementation of proper anti-CSRF tokens in all administrative interfaces aligns with ATT&CK technique T1078 which addresses legitimate credentials and privileges, while also following the principle of least privilege and secure coding practices. Security administrators should conduct thorough vulnerability assessments of all web-based management interfaces and ensure that CSRF protection mechanisms are consistently applied across all administrative functions to prevent similar attacks against other system components.