CVE-2020-29240 in Lepton
Summary
by MITRE • 12/02/2020
Lepton-CMS 4.7.0 is affected by cross-site scripting (XSS). An attacker can inject the XSS payload in the URL field of the admin page and each time an admin visits the Menu-Pages-Pages Overview section, the XSS will be triggered.
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Analysis
by VulDB Data Team • 05/04/2025
Lepton-CMS version 4.7.0 contains a critical cross-site scripting vulnerability that exposes the administrative interface to persistent XSS attacks. This vulnerability exists within the URL field processing functionality of the admin panel, specifically affecting the Menu-Pages-Pages Overview section where the malicious payload is executed. The flaw allows attackers to inject malicious JavaScript code through the URL input field, which then executes whenever administrators navigate to the affected page section. This represents a serious security weakness that can lead to complete administrative compromise and unauthorized access to sensitive system resources.
The technical implementation of this vulnerability stems from inadequate input validation and output sanitization within the CMS's administrative interface. When administrators view the Pages Overview section, the system fails to properly escape or filter the URL field content before rendering it in the web interface. This allows malicious actors to embed JavaScript payloads that execute in the context of the administrator's browser session. The vulnerability is particularly dangerous because it leverages the trust relationship between the administrator and the CMS, enabling attackers to execute arbitrary code with the privileges of the logged-in administrator. This type of vulnerability is classified under CWE-79 as "Improper Neutralization of Input During Web Page Generation" and aligns with ATT&CK technique T1059.007 for "Command and Scripting Interpreter: JavaScript."
The operational impact of this vulnerability extends beyond simple data theft or defacement. Successful exploitation can enable attackers to establish persistent access to the CMS administration panel, modify or delete content, create new administrative accounts, and potentially escalate privileges to gain access to underlying server resources. Attackers can leverage this vulnerability to perform session hijacking, steal sensitive administrative credentials, or deploy additional malicious payloads through the compromised administrative interface. The persistent nature of the XSS means that every administrator who visits the affected page section becomes a potential victim, making this vulnerability particularly dangerous in multi-user environments where multiple administrators may access the same CMS interface.
Mitigation strategies for this vulnerability should include immediate patching of the affected Lepton-CMS version to the latest available release that addresses the XSS flaw. Organizations should implement comprehensive input validation and output encoding mechanisms throughout the administrative interface to prevent similar issues in the future. Network-based mitigations such as web application firewalls can provide additional protection by filtering suspicious JavaScript payloads in HTTP requests. Security teams should conduct thorough penetration testing of the CMS administrative interface to identify other potential injection points and implement proper content security policies. Regular security audits and vulnerability assessments should be performed to ensure that all CMS components remain up-to-date with the latest security patches and that input sanitization measures are properly implemented across all user-facing interfaces. Additionally, implementing proper access controls and monitoring for unusual administrative activities can help detect potential exploitation attempts.