CVE-2020-2272 in ElasTest Plugin
Summary
by MITRE
A missing permission check in Jenkins ElasTest Plugin 1.2.1 and earlier allows attackers with Overall/Read permission to connect to an attacker-specified URL using attacker-specified credentials.
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Analysis
by VulDB Data Team • 09/16/2020
The vulnerability identified as CVE-2020-2272 resides within the Jenkins ElasTest Plugin version 1.2.1 and earlier, representing a critical authorization bypass flaw that undermines the security model of the Jenkins continuous integration platform. This issue stems from a fundamental missing permission check that allows unauthorized access to network resources through the plugin's functionality. The vulnerability specifically affects systems where the ElasTest plugin is installed and configured, creating a dangerous pathway for attackers who possess only the basic Overall/Read permission level. The ElasTest plugin is designed to facilitate testing and integration with various test environments, but this flaw enables malicious actors to exploit the plugin's network connectivity features without proper authorization.
The technical implementation of this vulnerability manifests through the plugin's failure to validate whether the requesting user has appropriate permissions before allowing network operations to proceed. When an attacker with Overall/Read permission attempts to utilize the plugin's URL connection capabilities, the system does not perform the necessary authorization checks that should validate whether the user should be permitted to establish connections to arbitrary external endpoints. This missing validation allows the attacker to specify any URL they choose and provide arbitrary credentials, effectively bypassing the normal access control mechanisms that protect Jenkins from unauthorized network interactions. The flaw operates at the application level within the Jenkins plugin architecture, specifically targeting the authentication and authorization flow during network operation execution.
The operational impact of CVE-2020-2272 extends far beyond simple information disclosure, as it enables attackers to potentially access internal network resources, exfiltrate sensitive data, or even establish command and control channels. An attacker could leverage this vulnerability to connect to internal services that are normally protected by firewall rules or network segmentation, effectively circumventing network-level security controls. The ability to specify arbitrary credentials means that attackers could potentially authenticate to internal systems using stolen or fabricated credentials, leading to further compromise of the Jenkins environment and potentially the broader network infrastructure. This vulnerability particularly impacts organizations that rely on Jenkins for CI/CD operations and have complex network architectures where the Jenkins server serves as a central point of integration.
Organizations should immediately implement mitigations including updating to the patched version of the ElasTest plugin, which addresses the missing permission check by implementing proper authorization validation before allowing network operations. The mitigation strategy should also include restricting the Overall/Read permission to only trusted users and implementing network segmentation to limit the potential impact of successful exploitation. Security teams should monitor Jenkins logs for suspicious network activity and implement network-level controls to prevent unauthorized outbound connections from the Jenkins server. This vulnerability aligns with CWE-668, which describes the weakness of "Exposure of Resource to Wrong Sphere" where a resource is made available to an entity that should not have access to it. The attack pattern corresponds to techniques described in the ATT&CK framework under "T1071.004 - Application Layer Protocol: DNS" and "T1046 - Network Service Scanning" as attackers could use this vulnerability to probe and access network resources they would normally be restricted from reaching, potentially leading to further exploitation of the network infrastructure.