Learn about CVE-2021-21043, a Reflected Cross-site Scripting (XSS) vulnerability in Adobe Experience Manager (AEM) versions 4.9.2 and earlier. Understand its impact, affected systems, and mitigation steps.
This article provides an overview of CVE-2021-21043, a Reflected Cross-site Scripting (XSS) vulnerability affecting Adobe Experience Manager (AEM) versions 4.9.2 and earlier.
Understanding CVE-2021-21043
CVE-2021-21043 is a security vulnerability identified in Adobe Experience Manager (AEM) that allows attackers to inject malicious JavaScript code into vulnerable form fields through the version-compare and page-compare tools.
What is CVE-2021-21043?
The vulnerability arises from improper handling of invalid JCR characters in ACS Commons version 4.9.2 and earlier. By exploiting this flaw, threat actors can execute arbitrary code within a victim's browser by tricking users into interacting with specially crafted content.
The Impact of CVE-2021-21043
With a CVSS base score of 6.1 (Medium severity), this XSS vulnerability poses a moderate risk. Although no direct impact on data confidentiality or integrity is reported, successful exploitation could lead to unauthorized code execution in the victim's browser.
Technical Details of CVE-2021-21043
This section delves into the technical aspects of the vulnerability, including its description, affected systems, and the exploitation mechanism.
Vulnerability Description
The vulnerability allows attackers to inject and execute malicious JavaScript code in the victim's browser through vulnerable form fields associated with the version-compare and page-compare tools in ACS Commons.
Affected Systems and Versions
Adobe Experience Manager (AEM) versions 4.9.2 and earlier are confirmed to be impacted by this XSS vulnerability due to improper handling of JCR characters in ACS Commons.
Exploitation Mechanism
To exploit CVE-2021-21043, attackers need to craft malicious content and persuade users to interact with it. By injecting specially coded inputs into vulnerable form fields, threat actors can execute arbitrary JavaScript code within the victim's browser.
Mitigation and Prevention
In response to CVE-2021-21043, it is crucial for organizations to take immediate steps to mitigate the risk and implement long-term security measures.
Immediate Steps to Take
Long-Term Security Practices
Patching and Updates
Adobe has released patches to address the XSS vulnerability in ACS Commons. Ensure all affected systems are updated to the latest non-vulnerable versions to prevent exploitation.