CVE-2018-18824 in WolfCMS
Summary
by MITRE
WolfCMS v0.8.3.1 allows XSS via an SVG file to /?/admin/plugin/file_manager/browse/.
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Analysis
by VulDB Data Team • 09/07/2023
The vulnerability CVE-2018-18824 represents a cross-site scripting flaw in WolfCMS version 0.8.3.1 that specifically targets the file manager component accessible through the administrative interface. This issue arises when users upload or browse SVG files within the plugin file manager functionality, creating an avenue for malicious actors to execute arbitrary JavaScript code in the context of other users' browsers. The vulnerability exists in the way the application handles SVG file processing and rendering within the administrative file browsing interface, where user-supplied SVG content is not properly sanitized or validated before being displayed to authenticated administrators. This particular attack vector is significant because it leverages the trusted administrative context of the CMS, allowing attackers to potentially escalate privileges or gain unauthorized access to sensitive administrative functions.
The technical implementation of this vulnerability stems from insufficient input validation and output encoding within the file manager plugin. When an SVG file is uploaded or accessed through the browse functionality, the system fails to properly sanitize the file content, particularly focusing on script tags, event handlers, and other malicious constructs that could be embedded within SVG markup. The vulnerability specifically affects the administrative interface at the URL path ?/admin/plugin/file_manager/browse/ where the application displays file listings including SVG files without adequate security measures. This flaw operates under CWE-79 which categorizes cross-site scripting vulnerabilities as weaknesses in input validation and output encoding. The attack can be executed through a crafted SVG file containing malicious JavaScript code that gets executed when the file is displayed or interacted with within the administrative context, potentially allowing attackers to hijack user sessions or perform unauthorized actions.
The operational impact of this vulnerability extends beyond simple script execution as it provides attackers with a potential pathway to compromise the entire administrative interface of the WolfCMS installation. An attacker who successfully exploits this vulnerability could gain access to sensitive administrative functions, modify content, create new administrator accounts, or even escalate privileges to full system control. The vulnerability is particularly dangerous because it requires minimal user interaction beyond accessing the file manager interface, making it suitable for automated exploitation. The attack follows the ATT&CK framework's technique T1059.007 for command and scripting interpreter execution, specifically targeting the execution of malicious scripts within the browser context of authenticated administrators. This vulnerability affects not only the immediate security of the CMS but also potentially compromises the entire website if administrators interact with the malicious SVG file, as the XSS payload could be used to steal session cookies or redirect users to malicious sites.
Mitigation strategies for CVE-2018-18824 should focus on implementing proper input validation and output encoding for all file uploads, particularly SVG files within administrative interfaces. Organizations should immediately upgrade to a patched version of WolfCMS if available, as this vulnerability was likely addressed in subsequent releases. The implementation of Content Security Policy headers can provide additional protection against script execution, while strict file type validation and sanitization of uploaded content should be enforced. The administrative interface should never trust user-supplied content without proper sanitization, and SVG files should either be converted to raster formats or have their scripting capabilities stripped during upload processes. Additionally, regular security audits should be conducted to identify similar vulnerabilities in other CMS components, particularly those involving file upload and display functionality. Network monitoring should be implemented to detect suspicious file upload activities and unusual administrative access patterns, while user access controls should be reviewed to ensure least privilege principles are maintained throughout the system.