CVE-2024-48927 in Umbraco
Summary
by MITRE • 10/22/2024
Umbraco, a free and open source .NET content management system, has a remote code execution issue in versions on the 13.x branch prior to 13.5.2, 10.x prior to 10.8.7, and 8.x prior to 8.18.15. There is a potential risk of code execution for Backoffice users when they “preview” SVG files in full screen mode. Versions 13.5.2, 10.8,7, and 8.18.15 contain a patch for the issue. As a workaround, derver-side file validation is available to strip script tags from file's content during the file upload process.
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Analysis
by VulDB Data Team • 03/03/2025
The vulnerability identified as CVE-2024-48927 represents a critical remote code execution flaw within the Umbraco content management system affecting multiple version branches. This security issue specifically targets the preview functionality for SVG files within the Backoffice interface, creating a pathway for malicious code execution when users interact with potentially compromised graphics files. The vulnerability impacts Umbraco versions 13.x prior to 13.5.2, 10.x prior to 10.8.7, and 8.x prior to 8.18.15, making it a widespread concern across the platform's major release lines. The flaw exploits the lack of proper input validation during SVG file processing, particularly when users engage the full-screen preview mode which inadvertently executes embedded scripts within the vector graphics format.
The technical implementation of this vulnerability stems from insufficient sanitization of SVG content during the file preview process. When users select the preview option for SVG files, the system renders the graphics directly within the browser environment without adequate filtering of potentially malicious script elements embedded within the SVG markup. This behavior creates a server-side code execution vector because SVG files can contain embedded javascript through various mechanisms including script tags, event handlers, and external references. The vulnerability specifically leverages the preview functionality's trust in user-uploaded content without proper validation, allowing attackers to inject malicious code that executes within the context of the Backoffice user's session. This represents a classic case of insufficient input validation and output encoding, aligning with CWE-20 (Improper Input Validation) and CWE-79 (Cross-Site Scripting) classifications.
The operational impact of CVE-2024-48927 extends beyond simple code execution, as it provides attackers with potential access to sensitive administrative functions within the Umbraco environment. An attacker who successfully exploits this vulnerability could gain unauthorized access to the Backoffice interface, potentially leading to full system compromise including data theft, content manipulation, and privilege escalation. The attack vector requires user interaction through the preview functionality, which means that successful exploitation depends on convincing an administrator or authorized user to open a malicious SVG file in preview mode. However, this requirement does not mitigate the severity, as administrators often handle numerous files and may inadvertently interact with compromised content. The vulnerability can be exploited in both targeted attacks against specific users and broader campaigns leveraging social engineering techniques to deliver malicious SVG files.
Organizations utilizing affected Umbraco versions face significant security risks that require immediate remediation efforts. The recommended solution involves upgrading to the patched versions 13.5.2, 10.8.7, and 8.18.15, which implement proper SVG sanitization mechanisms to prevent script execution during preview operations. Additionally, the workaround of implementing server-side file validation provides an interim mitigation strategy that strips script tags from file content during the upload process. This approach aligns with ATT&CK technique T1059.007 (Command and Scripting Interpreter: JavaScript) and T1566.001 (Phishing: Spearphishing Attachment) by addressing the execution of malicious code through file-based attack vectors. Security teams should also consider implementing additional controls such as network-based file filtering, user behavior monitoring, and regular security assessments to detect potential exploitation attempts. The vulnerability demonstrates the importance of validating all user-supplied content and implementing defense-in-depth strategies to protect against file-based attack vectors in web applications.