CVE-2023-43501 in Build Failure Analyzer Plugin
Summary
by MITRE • 09/20/2023
A missing permission check in Jenkins Build Failure Analyzer Plugin 2.4.1 and earlier allows attackers with Overall/Read permission to connect to an attacker-specified hostname and port using attacker-specified username and password.
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Analysis
by VulDB Data Team • 10/13/2023
The vulnerability identified as CVE-2023-43501 resides within the Jenkins Build Failure Analyzer Plugin version 2.4.1 and earlier, representing a critical authorization bypass flaw that fundamentally undermines the security model of the Jenkins platform. This issue manifests as a missing permission check that enables unauthorized access to network resources through a carefully crafted attack vector. The vulnerability specifically affects systems where the Build Failure Analyzer plugin is installed and configured, creating a pathway for malicious actors to exploit legitimate user permissions and gain access to arbitrary network endpoints.
The technical flaw stems from insufficient validation of user permissions within the plugin's network communication functions. When an attacker possesses the Overall/Read permission level, which is typically granted to users who can view the Jenkins system but not modify it, they can leverage this privilege to establish connections to any hostname and port specified by the attacker. This misconfiguration allows the attacker to use arbitrary username and password credentials, effectively bypassing normal authentication mechanisms that should protect against unauthorized network access attempts. The vulnerability essentially transforms a read-only permission into a potential reconnaissance and exploitation tool.
The operational impact of this vulnerability extends far beyond simple information disclosure, as it creates a potential attack vector for network reconnaissance and lateral movement within the infrastructure. An attacker could use this vulnerability to probe internal network services, potentially identifying sensitive systems, misconfigured services, or vulnerable network endpoints that are not directly exposed to the internet. The ability to specify arbitrary hostnames and ports means that attackers could target internal systems that should remain protected behind firewalls or network segmentation policies, effectively undermining network security boundaries. This capability aligns with ATT&CK technique T1046 Network Service Scanning and T1071 Application Layer Protocol, where attackers leverage legitimate system functions to expand their operational scope.
From a compliance and security standards perspective, this vulnerability directly contravenes the principle of least privilege and proper access control mechanisms that are fundamental to secure system design. The issue represents a failure to implement proper input validation and permission verification, which are core requirements under CWE-284 Improper Access Control. Organizations using Jenkins with this plugin version face significant risk of unauthorized network access, potential data exfiltration, and increased attack surface that could lead to more severe compromises within their infrastructure. The vulnerability's impact is particularly concerning in enterprise environments where Jenkins serves as a central automation platform and where the Build Failure Analyzer plugin is commonly deployed for monitoring and analysis purposes.
Mitigation strategies for CVE-2023-43501 should prioritize immediate plugin version updates to the latest available release that addresses this permission check deficiency. Organizations must also implement network segmentation controls to limit the potential impact of successful exploitation attempts, ensuring that even if an attacker gains access to Jenkins, they cannot easily move laterally within the network. Additional defensive measures include monitoring for unusual network connection patterns, implementing network access controls to restrict Jenkins from connecting to arbitrary external endpoints, and conducting thorough permission reviews to ensure that only authorized personnel have Overall/Read access to Jenkins systems. Security teams should also consider implementing intrusion detection systems that can identify anomalous network activity patterns that may indicate exploitation attempts. The vulnerability serves as a reminder of the critical importance of proper permission validation in distributed systems and the potential consequences when such controls are missing from security-sensitive applications.