CVE-2019-10399 in Script Security Plugin
Summary
by MITRE
A sandbox bypass vulnerability in Jenkins Script Security Plugin 1.62 and earlier related to the handling of property names in property expressions in increment and decrement expressions allowed attackers to execute arbitrary code in sandboxed scripts.
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Analysis
by VulDB Data Team • 08/22/2020
The vulnerability identified as CVE-2019-10399 represents a critical sandbox bypass flaw within the Jenkins Script Security Plugin affecting versions 1.62 and earlier. This issue specifically targets the plugin's handling of property names within property expressions that occur in increment and decrement operations, creating a pathway for unauthorized code execution within what should be isolated sandboxed environments. The flaw resides in the plugin's insufficient validation mechanisms that fail to properly sanitize property name inputs during these specific expression types, allowing malicious actors to exploit the weakness through crafted script content.
The technical implementation of this vulnerability stems from the plugin's inadequate parsing and validation of property expressions in increment and decrement contexts. When Jenkins processes scripts containing these operations, the security plugin fails to properly isolate or validate the property names being accessed, enabling attackers to inject malicious code that bypasses the intended sandbox boundaries. This represents a direct violation of the principle of least privilege and sandbox isolation that security plugins are designed to enforce. The vulnerability aligns with CWE-264, which covers permissions, privileges, and access controls, specifically addressing insufficient sandboxing mechanisms that allow privilege escalation through code execution bypasses.
From an operational perspective, this vulnerability poses significant risk to Jenkins environments that rely on the Script Security Plugin for protecting against malicious script execution. Attackers can leverage this flaw to execute arbitrary code within the Jenkins server's context, potentially leading to full system compromise, data exfiltration, or lateral movement within the network. The impact extends beyond simple code execution as it undermines the fundamental security model that Jenkins administrators depend upon to protect their CI/CD pipelines. The vulnerability is particularly dangerous in enterprise environments where Jenkins serves as a central automation platform for build and deployment processes, as successful exploitation could result in complete infrastructure compromise.
The mitigation strategy for CVE-2019-10399 involves immediate upgrade of the Jenkins Script Security Plugin to version 1.63 or later, which contains the necessary patches to address the property name validation issues. Organizations should also implement comprehensive monitoring of script execution within Jenkins environments to detect anomalous behavior that might indicate exploitation attempts. Additionally, security teams should review and tighten Jenkins security configurations, ensuring that only authorized users have access to script execution capabilities. The remediation process should include thorough testing of the updated plugin to ensure compatibility with existing scripts and pipelines while maintaining the security posture. This vulnerability demonstrates the critical importance of maintaining up-to-date security plugins and the potential consequences of outdated software components in continuous integration environments. Organizations should also consider implementing additional layers of security controls such as network segmentation and privilege management to reduce the impact of potential exploitation.