CVE-2025-24012 in Umbraco
Summary
by MITRE • 01/21/2025
Umbraco is a free and open source .NET content management system. Starting in version 14.0.0 and prior to versions 14.3.2 and 15.1.2, authenticated users are able to exploit a cross-site scripting vulnerability when viewing certain localized backoffice components. Versions 14.3.2 and 15.1.2 contain a patch.
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Analysis
by VulDB Data Team • 02/09/2025
The vulnerability identified as CVE-2025-24012 affects Umbraco content management systems across specific version ranges, representing a cross-site scripting flaw that impacts authenticated users within the backoffice environment. This issue manifests when users access certain localized components of the administrative interface, creating a potential vector for malicious code execution. The vulnerability exists in versions 14.0.0 through 14.3.1 and 15.0.0 through 15.1.1, with patch releases available in 14.3.2 and 15.1.2 that address the identified weakness. The flaw specifically targets the localized backoffice components, suggesting that the vulnerability stems from improper handling of user-supplied data within the localization framework of the CMS.
Technical exploitation of this vulnerability occurs through authenticated user sessions, meaning that an attacker must first gain valid credentials to the Umbraco system before being able to leverage this XSS flaw. The cross-site scripting vulnerability allows attackers to inject malicious scripts into the backoffice interface, potentially enabling them to steal session cookies, perform actions on behalf of authenticated users, or redirect them to malicious sites. The localized components mentioned in the description indicate that the vulnerability may be related to how the system processes internationalization data or user interface elements that are dynamically rendered based on language settings. This type of vulnerability falls under the CWE-79 category of Cross-site Scripting, specifically representing a reflected XSS attack vector where malicious input is processed and then reflected back to users in the backoffice context.
The operational impact of this vulnerability extends beyond simple data theft, as it provides attackers with potential access to sensitive administrative functions within the Umbraco system. An authenticated attacker could leverage this vulnerability to escalate privileges, modify content, or manipulate system configurations through the backoffice interface. The localized nature of the vulnerability suggests that it may be particularly concerning in multi-language deployments where translation files or locale-specific data might not be properly sanitized before being rendered in the admin interface. This vulnerability represents a significant risk to organizations relying on Umbraco for content management, as it could allow attackers to compromise the entire administrative environment through a single authenticated session.
Organizations should immediately implement the patches available in versions 14.3.2 and 15.1.2 to remediate this vulnerability, as these releases contain the necessary fixes for the XSS flaw in localized backoffice components. System administrators should conduct thorough testing of the updated versions to ensure that the patch does not introduce any compatibility issues with existing customizations or third-party integrations. Additional mitigations include implementing proper input validation and output encoding for all user-supplied data within the backoffice environment, as well as monitoring for suspicious activities in administrative sessions. Network segmentation and least-privilege access controls should be maintained to limit the potential impact of any successful exploitation attempts. The vulnerability also aligns with ATT&CK technique T1566.001 for initial access through malicious web content, and T1078.004 for valid accounts as a means of gaining access to administrative interfaces, emphasizing the importance of both account security and input sanitization measures.