CVE-2021-28626 in Experience Manager Cloud Service
Summary
by MITRE • 08/25/2021
Adobe Experience Manager Cloud Service offering, as well as versions 6.5.8.0 (and below) is affected by an Improper Authorization vulnerability allowing users to create nodes under a location. An unauthenticated attacker could leverage this vulnerability to cause an application denial-of-service. Exploitation of this issue does not require user interaction.
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Analysis
by VulDB Data Team • 08/27/2021
Adobe Experience Manager Cloud Service and versions 6.5.8.0 and below contain a critical improper authorization vulnerability that allows attackers to create nodes under restricted locations without proper authentication. This vulnerability stems from insufficient access control mechanisms that fail to properly validate user permissions before permitting node creation operations. The flaw exists within the content management system's authorization framework where the application does not adequately verify whether an entity has the necessary privileges to perform node creation actions in specific directories or locations. This weakness enables unauthorized entities to bypass normal access controls and establish new content nodes in protected areas of the repository. The vulnerability is particularly dangerous because it operates without requiring any user interaction, making it highly exploitable through automated attacks. An unauthenticated attacker can directly submit requests to the affected system to create nodes under restricted locations, potentially leading to significant system disruption and unauthorized content manipulation.
The technical implementation of this vulnerability demonstrates a clear violation of the principle of least privilege and proper access control enforcement. According to CWE-285, this represents an improper authorization condition where the system fails to properly enforce access control policies. The flaw allows for arbitrary node creation in restricted locations, which can be leveraged to manipulate the content repository structure and potentially establish persistent access points. The denial-of-service impact occurs when attackers create excessive nodes or manipulate repository structures in ways that consume system resources or corrupt the content hierarchy. This vulnerability affects the fundamental integrity of the content management system's security model and can be exploited to disrupt normal operations without requiring any authentication credentials or user engagement.
The operational impact of CVE-2021-28626 extends beyond simple denial-of-service conditions to potentially enable more sophisticated attacks within the Adobe Experience Manager environment. Attackers can leverage this vulnerability to establish unauthorized content nodes that may serve as footholds for further exploitation or to corrupt existing content structures. The lack of authentication requirements means that this vulnerability can be exploited at scale without detection, potentially leading to complete system compromise or unauthorized content publishing. Organizations using affected versions of Adobe Experience Manager face significant risk of unauthorized content modification, system resource exhaustion, and potential data integrity violations. The vulnerability's ability to operate without user interaction makes it particularly attractive to automated attack tools and increases the potential for widespread impact across multiple systems.
Mitigation strategies for this vulnerability require immediate implementation of Adobe's security patches and updates for affected versions. Organizations should implement additional access control measures such as network segmentation and firewall rules to limit access to sensitive AEM endpoints. The system configuration should be reviewed to ensure proper authorization enforcement and access control policies are properly implemented. Security monitoring should be enhanced to detect unusual node creation patterns or unauthorized content modifications. According to ATT&CK framework, this vulnerability relates to T1078 (Valid Accounts) and T1499 (Endpoint Denial of Service) techniques, as it enables unauthorized access and service disruption. Regular security assessments should be conducted to verify proper implementation of access controls and to identify potential additional weaknesses in the content management system's security posture. Organizations should also consider implementing automated patch management processes to ensure timely remediation of similar vulnerabilities in the future.