CVE-2021-39166 in Pimcore
Summary
by MITRE • 09/01/2021
Pimcore is an open source data & experience management platform. Prior to version 10.1.2, text-values were not properly escaped before printed in the version preview. This allowed XSS by authenticated users with access to the resources. This issue is patched in Pimcore version 10.1.2.
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Analysis
by VulDB Data Team • 09/04/2021
The vulnerability CVE-2021-39166 affects Pimcore, an open source data and experience management platform that serves as a comprehensive content management and digital asset management solution for enterprises. This flaw represents a critical security oversight in how the platform handles text value rendering within its version preview functionality. The vulnerability specifically impacts versions prior to 10.1.2, indicating that Pimcore's development team identified and addressed this issue through a targeted patch release. The flaw exists within the platform's rendering engine where user-supplied text values are not properly sanitized before being displayed in version preview contexts, creating a persistent cross-site scripting vulnerability that can be exploited by authenticated users with appropriate access rights.
The technical nature of this vulnerability stems from inadequate input validation and output sanitization within Pimcore's version preview system. When authenticated users with sufficient privileges create or modify content, the platform fails to properly escape special characters and HTML markup within text fields before rendering them in the preview interface. This improper handling allows malicious payloads to be injected and executed within the browser context of other users who view the version preview. The vulnerability is classified as a cross-site scripting issue under CWE-79, which specifically addresses improper neutralization of input during web page generation. The flaw operates at the application layer where user input transitions into rendered output without appropriate security controls, making it particularly dangerous in enterprise environments where multiple users interact with shared content management systems.
The operational impact of CVE-2021-39166 extends beyond simple script execution capabilities as it enables authenticated attackers to potentially escalate their privileges and compromise the entire Pimcore environment. An attacker with access to resources within the platform can inject malicious JavaScript code that executes in the context of other users' browsers, potentially leading to session hijacking, data exfiltration, or further exploitation of the compromised system. The vulnerability affects the platform's integrity and availability since malicious actors can manipulate content previews to redirect users to phishing sites or inject malware delivery mechanisms. This weakness also undermines the trust model of the platform, as legitimate users may unknowingly interact with malicious content that appears to be part of normal platform functionality. The attack vector requires authentication, which reduces the attack surface compared to unauthenticated vulnerabilities, but still represents a significant risk within enterprise environments where user access controls may be complex and difficult to monitor effectively.
Organizations using affected Pimcore versions should immediately implement the patch released in version 10.1.2 to address this vulnerability. The mitigation strategy should include comprehensive testing of the patched version in staging environments to ensure no regression issues occur with existing functionality. Security teams should also conduct thorough audits of user access permissions to minimize the potential impact of any exploitation attempts, as the vulnerability requires authenticated access to resources. Network monitoring should be enhanced to detect unusual patterns in content management activities that might indicate exploitation attempts. The vulnerability demonstrates the importance of proper input sanitization and output escaping in web applications, aligning with ATT&CK technique T1059.007 for script injection and T1566 for credential harvesting through malicious content. Organizations should also consider implementing additional security controls such as content security policies and regular security assessments to prevent similar issues in other components of their digital infrastructure.