CVE-2021-43293 in Nexus Repository Manager
Summary
by MITRE • 11/04/2021
Sonatype Nexus Repository Manager 3.x before 3.36.0 allows a remote authenticated attacker to potentially perform network enumeration via Server Side Request Forgery (SSRF).
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Analysis
by VulDB Data Team • 11/09/2021
The vulnerability identified as CVE-2021-43293 affects Sonatype Nexus Repository Manager version 3.x prior to 3.36.0, presenting a significant security risk through Server Side Request Forgery (SSRF) capabilities. This flaw enables authenticated attackers to potentially enumerate network resources by manipulating the repository manager's server-side processing mechanisms. The vulnerability stems from insufficient input validation and improper handling of user-supplied data within the application's network communication pathways, creating opportunities for attackers to redirect requests to internal systems or external malicious endpoints.
The technical implementation of this vulnerability involves the manipulation of network requests through the Nexus Repository Manager's authentication mechanisms, where authenticated users can craft specific inputs that bypass normal network restrictions. The flaw allows attackers to leverage the repository manager's legitimate network access capabilities to probe internal network topology, scan internal services, and potentially access sensitive internal resources that would otherwise be restricted from external access. This represents a classic SSRF vulnerability pattern where the server processes user-controllable requests without proper validation of destination endpoints.
The operational impact of this vulnerability extends beyond simple network enumeration, as it provides attackers with valuable reconnaissance data that can be used for subsequent exploitation attempts. An authenticated attacker can potentially map internal network structures, identify running services, and gather information about internal systems that may contain additional vulnerabilities. This reconnaissance capability significantly increases the attack surface and enables more sophisticated attacks such as internal service exploitation or lateral movement within the network environment. The vulnerability affects organizations that rely on Nexus Repository Manager for package management and repository hosting, particularly those with complex internal network architectures.
Mitigation strategies for CVE-2021-43293 include immediate deployment of Nexus Repository Manager version 3.36.0 or later, which contains the necessary patches to address the SSRF vulnerability. Organizations should also implement network segmentation and firewall rules to restrict access to internal systems from the repository manager, while enforcing strict input validation on all user-supplied data. The implementation of web application firewalls and network monitoring solutions can help detect and prevent suspicious network requests originating from the repository manager. Additionally, organizations should conduct regular security assessments of their repository management systems and implement principle of least privilege access controls to minimize the potential impact of authenticated attacks. This vulnerability aligns with CWE-918, which specifically addresses Server-Side Request Forgery, and falls under ATT&CK technique T1046 for Network Service Scanning, making it a critical concern for organizations implementing secure software supply chain management practices.