CVE-2021-21083 in Experience Manager
Summary
by MITRE • 06/28/2021
AEM's Cloud Service offering, as well as versions 6.5.7.0 (and below), 6.4.8.3 (and below) and 6.3.3.8 (and below) are affected by an Improper Access Control vulnerability. An unauthenticated attacker could leverage this vulnerability to cause an application denial-of-service in the context of the current user.
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Analysis
by VulDB Data Team • 07/03/2021
The vulnerability identified as CVE-2021-21083 affects Adobe Experience Manager (AEM) cloud service offerings and specific legacy versions including 6.5.7.0 and earlier, 6.4.8.3 and earlier, and 6.3.3.8 and earlier. This represents a critical improper access control flaw that undermines the security posture of AEM implementations. The vulnerability stems from insufficient authorization checks within the application's security framework, allowing unauthorized actors to exploit weaknesses in the access control mechanisms that should normally protect system resources and functionality.
The technical nature of this vulnerability manifests as an improper access control condition where authentication requirements are bypassed or inadequately enforced. Attackers can leverage this flaw without requiring valid credentials to execute malicious actions that result in denial-of-service conditions. The vulnerability operates at the application layer where the system fails to properly validate user permissions and access rights, creating an entry point for unauthorized operations that can disrupt normal application functionality and availability. This weakness specifically impacts the service's ability to maintain proper access boundaries and can be exploited to cause system disruption.
The operational impact of CVE-2021-21083 extends beyond simple service disruption to potentially compromise the entire AEM environment. An unauthenticated attacker can trigger denial-of-service conditions that affect application availability and user experience, potentially leading to business continuity issues. The vulnerability affects both cloud service offerings and on-premises installations, indicating a widespread exposure across different deployment models. Organizations relying on these affected AEM versions face elevated risk of service interruption, which can result in significant operational and financial consequences. The lack of authentication requirements for exploitation means that any system with vulnerable AEM installations can be targeted by malicious actors without prior access credentials.
Mitigation strategies for this vulnerability should prioritize immediate patching of affected AEM versions to the latest security releases. Organizations should implement network segmentation and access controls to limit exposure of vulnerable systems to external threats. Security monitoring should be enhanced to detect anomalous access patterns that may indicate exploitation attempts. The vulnerability aligns with CWE-284 (Improper Access Control) and maps to attack techniques in the ATT&CK framework under privilege escalation and denial-of-service categories. Regular security assessments and vulnerability scanning should be conducted to identify and remediate similar access control weaknesses. Additionally, implementing proper input validation and access control enforcement mechanisms can help prevent similar vulnerabilities from emerging in future application developments. Organizations should also consider implementing web application firewalls and additional security controls to provide defense-in-depth against exploitation attempts targeting this specific access control flaw.