CVE-2025-9868 in Nexus Repository
Summary
by MITRE • 10/08/2025
Server-Side Request Forgery (SSRF) in the Remote Browser Plugin in Sonatype Nexus Repository 2.x up to and including 2.15.2 allows unauthenticated remote attackers to exfiltrate proxy repository credentials via crafted HTTP requests.
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Analysis
by VulDB Data Team • 10/08/2025
The vulnerability identified as CVE-2025-9868 represents a critical server-side request forgery flaw within Sonatype Nexus Repository's Remote Browser Plugin component. This issue affects versions 2.x up to and including 2.15.2, creating a significant security risk for organizations relying on this repository management solution. The vulnerability stems from inadequate input validation and sanitization mechanisms within the plugin's handling of HTTP requests, allowing malicious actors to manipulate the application's behavior through crafted requests that bypass normal security controls.
The technical implementation of this vulnerability involves the Remote Browser Plugin's failure to properly validate and sanitize user-supplied input when processing HTTP requests. Attackers can exploit this weakness by crafting specifically formatted requests that trick the application into making unintended outbound connections to internal services or resources. The flaw specifically enables attackers to exfiltrate proxy repository credentials, which represents a severe compromise of the repository's security posture. This occurs because the plugin does not adequately restrict the destinations to which it can make requests, allowing connections to internal network resources that should remain protected from external access.
The operational impact of this vulnerability extends beyond simple credential theft, as it provides attackers with potential access to internal network resources and sensitive repository configurations. Organizations utilizing affected versions of Nexus Repository may experience unauthorized data exfiltration, privilege escalation opportunities, and potential lateral movement within their network infrastructure. The unauthenticated nature of the attack means that no prior credentials or access are required to exploit this vulnerability, making it particularly dangerous for environments where such repositories are exposed to untrusted networks or the internet. This flaw directly violates security principles of least privilege and network segmentation, as it allows external attackers to bypass normal access controls and reach internal repository components.
The vulnerability aligns with CWE-918, which specifically addresses server-side request forgery conditions, and maps to ATT&CK technique T1071.004 for application layer protocol manipulation. Organizations should immediately implement mitigations including updating to patched versions of Nexus Repository, implementing network segmentation to restrict access to the repository, and deploying web application firewalls to monitor and filter suspicious requests. Additional protective measures include disabling the Remote Browser Plugin if not essential, implementing strict outbound connection policies, and conducting thorough security assessments of repository configurations to identify potential additional attack vectors. The remediation process should prioritize immediate patching while maintaining comprehensive monitoring of repository access patterns to detect any exploitation attempts.
This vulnerability demonstrates the critical importance of validating all external inputs and implementing proper access controls in web applications. The flaw represents a failure in the principle of input validation and access restriction, where the application should have validated that requests were directed only to authorized external resources and not permitted to access internal network components. Organizations should conduct regular security assessments of their repository infrastructure and implement comprehensive monitoring solutions to detect anomalous access patterns that might indicate exploitation attempts. The incident underscores the necessity of maintaining up-to-date security patches and implementing defense-in-depth strategies to protect critical infrastructure components from such remote exploitation vulnerabilities.