CVE-2018-20233 in Universal Plugin Manager
Summary
by MITRE
The Upload add-on resource in Atlassian Universal Plugin Manager before version 2.22.14 allows remote attackers who have system administrator privileges to read files, make network requests and perform a denial of service attack via an XML External Entity vulnerability in the parsing of atlassian plugin xml files in an uploaded JAR.
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Analysis
by VulDB Data Team • 05/03/2020
The vulnerability identified as CVE-2018-20233 represents a critical security flaw in Atlassian Universal Plugin Manager affecting versions prior to 2.22.14. This issue manifests as an XML External Entity processing vulnerability within the upload functionality of the Universal Plugin Manager component. The vulnerability specifically impacts the parsing of atlassian plugin xml files contained within uploaded JAR archives, creating a pathway for malicious exploitation that leverages the XML parsing mechanism to execute unauthorized operations.
The technical exploitation of this vulnerability requires an attacker to possess system administrator privileges, which significantly reduces the attack surface but does not eliminate the risk entirely. The flaw operates through the improper handling of XML entities during the parsing of plugin configuration files, allowing attackers to craft malicious JAR files that contain specially crafted XML content. When the Universal Plugin Manager processes these files, it inadvertently resolves external entity references, enabling the execution of arbitrary file reads, network communications, and denial of service conditions. This vulnerability directly maps to CWE-611, which categorizes insecure direct object references and XML external entity processing issues.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with comprehensive control over the affected system's file system access and network capabilities. Successful exploitation enables attackers to read arbitrary files from the system, potentially accessing sensitive configuration data, user credentials, or system files that could lead to further compromise. Additionally, the ability to perform network requests allows attackers to exfiltrate data or establish command and control communications, while denial of service capabilities can disrupt system availability and impact business operations. The vulnerability effectively transforms a legitimate plugin upload functionality into a weaponized attack vector that can be leveraged for persistent system compromise.
Organizations affected by this vulnerability should prioritize immediate remediation through the upgrade to Atlassian Universal Plugin Manager version 2.22.14 or later, which includes the necessary patches to address the XML external entity processing flaw. Security teams should also implement additional monitoring controls to detect suspicious plugin upload activities and review existing plugin configurations to ensure no malicious JAR files have been uploaded to the system. The vulnerability demonstrates the importance of input validation and secure XML parsing practices, aligning with ATT&CK technique T1059.007 for execution through XML external entity processing. Organizations should also consider implementing network segmentation and access controls to limit the potential impact of privilege escalation attacks, as the vulnerability requires administrative privileges to exploit effectively.