CVE-2020-36408 in CMS Made Simple
Summary
by MITRE • 07/03/2021
A stored cross scripting (XSS) vulnerability in CMS Made Simple 2.2.14 allows authenticated attackers to execute arbitrary web scripts or HTML via a crafted payload entered into the "Add Shortcut" parameter under the "Manage Shortcuts" module.
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Analysis
by VulDB Data Team • 07/09/2021
This vulnerability represents a critical stored cross site scripting flaw in CMS Made Simple version 2.2.14 that fundamentally compromises the security of authenticated users. The issue resides within the "Manage Shortcuts" module where the application fails to properly sanitize user input when processing the "Add Shortcut" parameter. An attacker with valid credentials can exploit this weakness by crafting malicious payloads that get stored within the application's database and subsequently executed whenever the affected page is accessed by other users. The vulnerability classification aligns with CWE-79 which specifically addresses cross site scripting flaws where untrusted data is improperly integrated into web pages without adequate sanitization or encoding measures.
The operational impact of this vulnerability extends beyond simple script execution as it provides attackers with persistent access to the application's environment through the authenticated user context. When victims navigate to pages containing the stored malicious content, their browsers execute the embedded scripts within the security context of the vulnerable application, potentially enabling session hijacking, data exfiltration, or further attack vector exploitation. This stored nature of the vulnerability means that the malicious payload remains active until manually removed from the application's database, creating a persistent threat that can affect multiple users over extended periods. The attack surface is particularly concerning given that the vulnerability requires only authenticated access, which is often less strictly controlled than external network access.
From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1566 which covers social engineering tactics involving the exploitation of user trust through malicious content. The flaw enables attackers to leverage legitimate user sessions for malicious purposes, potentially bypassing traditional network-based security controls. The attack chain typically involves initial compromise through credential theft or social engineering, followed by authentication to the CMS application, and finally the injection of malicious code through the shortcut management interface. Organizations implementing CMS Made Simple should consider this vulnerability as a potential entry point for more sophisticated attacks targeting administrative privileges or user data.
Mitigation strategies should include immediate patching of the CMS Made Simple application to version 2.2.15 or later where this vulnerability has been addressed through proper input sanitization and validation. Additionally, administrators should implement robust input validation controls at multiple layers including application-level filtering, database-level sanitization, and web application firewall rules that monitor for suspicious payload patterns. Regular security audits of user permissions and access controls should be conducted to limit the impact of potential compromise, while monitoring systems should be configured to detect unusual activity patterns that might indicate successful exploitation attempts. The vulnerability serves as a reminder of the critical importance of input validation in web applications and demonstrates how seemingly minor functionality can create significant security risks when proper sanitization measures are not implemented.