CVE-2018-16620 in Nexus Repository Manager
Summary
by MITRE
Sonatype Nexus Repository Manager before 3.14 has Incorrect Access Control.
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Analysis
by VulDB Data Team • 04/13/2020
The vulnerability identified as CVE-2018-16620 affects Sonatype Nexus Repository Manager versions prior to 3.14, representing a critical access control flaw that undermines the security posture of organizations relying on this widely used artifact repository management system. This issue stems from improper authorization mechanisms within the application's permission model, allowing unauthorized users to gain elevated privileges and access restricted functionality. The vulnerability exists in the way the system validates user permissions and determines access rights to various repository operations, creating a pathway for privilege escalation attacks. Organizations utilizing Nexus Repository Manager for managing software artifacts, dependencies, and build outputs face significant risk when running vulnerable versions, as this flaw can enable attackers to bypass security controls and access sensitive repository data.
The technical implementation of this access control flaw manifests through insufficient validation of user roles and permissions during repository operations. Attackers can exploit this weakness by crafting specific requests that manipulate authorization checks, potentially gaining access to repositories they should not be able to view or modify. The vulnerability specifically impacts the repository management interfaces and administrative functions, where proper access controls should prevent unauthorized users from performing critical operations such as creating, modifying, or deleting repository configurations. This flaw operates at the application layer and can be exploited through various attack vectors including web interface manipulation, API calls, and potentially automated scanning tools that can identify and exploit the permission bypass. The underlying architecture fails to properly enforce the principle of least privilege, allowing authenticated users to escalate their privileges through carefully constructed requests that circumvent the intended access control mechanisms.
The operational impact of CVE-2018-16620 extends far beyond simple unauthorized access, as it can enable complete compromise of software supply chain security within affected organizations. Attackers exploiting this vulnerability can access proprietary software artifacts, modify repository configurations to inject malicious components, or even delete critical repository data. The implications are particularly severe for organizations that use Nexus Repository Manager as a central hub for managing dependencies and artifacts across development environments, as this single point of failure can compromise the integrity of entire software development pipelines. This vulnerability can facilitate supply chain attacks where malicious actors inject compromised components into repositories, potentially affecting thousands of downstream consumers. The impact is further amplified by the widespread adoption of Nexus Repository Manager across enterprises, making this vulnerability a prime target for automated exploitation campaigns.
Organizations should immediately implement mitigations including upgrading to Nexus Repository Manager version 3.14 or later, which contains the necessary access control fixes. Additionally, implementing network segmentation and restricting access to repository management interfaces can help limit the potential impact of exploitation attempts. Security monitoring should be enhanced to detect unusual access patterns and privilege escalation attempts within repository management systems. The vulnerability aligns with CWE-284 which describes improper access control, and can be mapped to ATT&CK technique T1078 for valid accounts and T1548 for privilege escalation. Organizations should also consider implementing additional security controls such as multi-factor authentication for administrative access, regular permission reviews, and comprehensive logging of repository access activities to detect potential exploitation attempts. Regular vulnerability assessments and penetration testing should be conducted to identify similar access control weaknesses in other components of the software supply chain infrastructure.