CVE-2020-24445 in Experience Manager
Summary
by MITRE • 12/10/2020
AEM's Cloud Service offering, as well as versions 6.5.6.0 (and below), 6.4.8.2 (and below) and 6.3.3.8 (and below) are affected by a stored Cross-Site Scripting (XSS) vulnerability that could be abused by an attacker to inject malicious scripts into vulnerable form fields. Malicious JavaScript may be executed in a victim’s browser when they browse to the page containing the vulnerable field.
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Analysis
by VulDB Data Team • 12/15/2020
This vulnerability exists within Adobe Experience Manager (AEM) across multiple versions including the Cloud Service offering and specific releases below 6.5.6.0, 6.4.8.2, and 6.3.3.8. The flaw represents a stored cross-site scripting vulnerability that allows attackers to inject malicious JavaScript code into form fields within the AEM environment. The vulnerability stems from inadequate input validation and output encoding mechanisms that fail to properly sanitize user-supplied data before it is rendered back to users. This type of vulnerability falls under CWE-79 which specifically addresses cross-site scripting flaws where web applications fail to properly encode output data, allowing attackers to inject malicious scripts that execute in the context of other users' browsers.
The operational impact of this vulnerability is significant as it enables attackers to execute arbitrary JavaScript code in victims' browsers when they view pages containing the maliciously injected content. This could lead to session hijacking, credential theft, data exfiltration, or the redirection of users to malicious websites. Attackers could exploit this vulnerability by submitting crafted payloads through form fields that are then stored and subsequently rendered without proper sanitization. The stored nature of this vulnerability means that once the malicious content is injected, it persists and affects all users who view the affected pages, making it particularly dangerous for content management systems where multiple users interact with shared content repositories.
The exploitation of this vulnerability aligns with ATT&CK technique T1531 which involves techniques for establishing persistence and maintaining access through the manipulation of web applications. The vulnerability creates opportunities for attackers to establish backdoors, steal sensitive information, or perform further attacks against the compromised environment. Organizations using affected AEM versions face risks of unauthorized access to sensitive content, potential data breaches, and compromise of user sessions. The vulnerability particularly affects environments where user-generated content is accepted through forms, as these provide the injection points for malicious scripts. Security teams must consider the broader implications for their web application security posture, as this vulnerability demonstrates insufficient input validation and output encoding practices that could potentially affect other components of the AEM platform.
Organizations should implement immediate mitigations including applying the latest security patches from Adobe, implementing comprehensive input validation and output encoding mechanisms, and conducting thorough security reviews of all user input handling processes. Additional defensive measures include implementing content security policies, regular security scanning of web applications, and establishing proper access controls and monitoring for suspicious activities. The vulnerability underscores the importance of maintaining up-to-date security practices and demonstrates the critical need for proper sanitization of all user-supplied content in web applications to prevent XSS attacks.