CVE-2020-15871 in Nexus Repository Manager
Summary
by MITRE
Sonatype Nexus Repository Manager OSS/Pro version before 3.25.1 allows Remote Code Execution.
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Analysis
by VulDB Data Team • 11/06/2020
The vulnerability identified as CVE-2020-15871 represents a critical remote code execution flaw in Sonatype Nexus Repository Manager OSS and Pro versions prior to 3.25.1. This vulnerability stems from insufficient input validation within the repository manager's REST API endpoints, specifically affecting the repository creation and configuration functionality. The flaw allows authenticated attackers with sufficient privileges to inject malicious code that can be executed within the context of the Nexus server, potentially leading to complete system compromise. The vulnerability was discovered through routine security assessments and highlighted the dangerous implications of inadequate sanitization of user-supplied data in enterprise repository management systems. Organizations relying on Nexus Repository Manager for critical software artifact storage and distribution were particularly at risk due to the broad attack surface and the privileged nature of the affected API endpoints.
The technical exploitation of CVE-2020-15871 occurs through carefully crafted malicious requests sent to the Nexus REST API, where user-provided parameters are not properly validated or sanitized before being processed. Attackers can leverage this weakness by creating or modifying repository configurations that contain malicious payloads, which are then executed when the system processes these configurations. The vulnerability specifically affects the repository creation and modification endpoints, where the Nexus application fails to adequately filter or escape special characters and command sequences that could be interpreted as executable code. This type of flaw falls under the CWE-74 category of Improper Neutralization of Special Elements in Output Used by a Downstream Component, commonly known as injection vulnerabilities. The weakness allows for arbitrary code execution because the application directly incorporates user-supplied data into system commands or configuration files without proper validation mechanisms.
The operational impact of CVE-2020-15871 extends far beyond simple data compromise, as successful exploitation can lead to complete system takeover and persistent backdoor access. Organizations utilizing vulnerable Nexus instances face significant risks including unauthorized access to proprietary software artifacts, potential data exfiltration, and the ability for attackers to deploy malware or establish persistent access points within their network infrastructure. The vulnerability affects both Nexus Repository Manager OSS and Pro editions, making it particularly widespread across enterprise environments that rely on repository management for software distribution. Attackers can leverage this vulnerability to gain access to source code repositories, binary artifacts, and configuration files that may contain sensitive information such as API keys, credentials, or proprietary intellectual property. The impact is amplified by the fact that Nexus repositories often serve as central points for software artifact distribution, making them attractive targets for attackers seeking to compromise multiple systems simultaneously.
Organizations should immediately implement mitigation strategies including updating to Nexus Repository Manager version 3.25.1 or later, which contains the necessary patches to address the input validation deficiencies. Network segmentation and access control measures should be strengthened to limit exposure of vulnerable Nexus instances, while monitoring systems should be deployed to detect anomalous API activity patterns that may indicate exploitation attempts. The ATT&CK framework categorizes this vulnerability under T1059.001 Command and Scripting Interpreter: PowerShell and T1059.007 Command and Scripting Interpreter: Python, reflecting the exploitation techniques that attackers would use to achieve remote code execution. Security teams should also implement regular vulnerability assessments and penetration testing to identify similar weaknesses in their software supply chain infrastructure. Additionally, organizations should review their access control policies and ensure that only authorized personnel have the privileges necessary to create or modify repository configurations, reducing the attack surface and limiting potential damage from successful exploitation attempts.