CVE-2020-13883 in API Manager
Summary
by MITRE
In WSO2 API Manager 3.0.0 and earlier, WSO2 API Microgateway 2.2.0, and WSO2 IS as Key Manager 5.9.0 and earlier, Management Console allows XXE during addition or update of a Lifecycle.
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Analysis
by VulDB Data Team • 10/22/2020
The vulnerability identified as CVE-2020-13883 represents a critical XML External Entity processing flaw within several WSO2 products including API Manager, Microgateway, and Identity Server Key Manager components. This vulnerability exists in the Management Console functionality where users can add or update Lifecycle configurations, creating an attack surface that adversaries can exploit to perform various malicious activities. The flaw stems from insufficient input validation and improper handling of XML data structures within the console's lifecycle management features.
The technical implementation of this vulnerability allows attackers to inject malicious XML entities during the lifecycle update process, which can then be processed by the underlying XML parser without proper sanitization. This creates opportunities for server-side request forgery attacks, information disclosure, and potentially remote code execution depending on the target system configuration. The vulnerability specifically affects versions 3.0.0 and earlier for WSO2 API Manager, 2.2.0 for WSO2 API Microgateway, and 5.9.0 and earlier for WSO2 Identity Server as Key Manager. The XXE processing occurs when the system attempts to parse user-supplied XML data containing external entity references that point to internal system resources or external malicious servers.
The operational impact of this vulnerability is significant as it enables attackers to access sensitive internal system information, perform unauthorized data exfiltration, and potentially escalate privileges within the affected systems. Attackers can leverage this vulnerability to probe internal network structures, access local files, and potentially gain unauthorized access to system resources that should remain protected. The vulnerability is particularly dangerous in enterprise environments where WSO2 products are commonly used for API management and identity services, as it can compromise the entire service infrastructure. The attack vector requires authentication to the Management Console, making it less accessible than fully public vulnerabilities but still posing a substantial risk to organizations with compromised credentials or insider threats.
Organizations should immediately implement mitigations including upgrading to patched versions of the affected WSO2 products, implementing proper XML parser configurations that disable external entity processing, and applying network-level restrictions to limit access to Management Console interfaces. The vulnerability aligns with CWE-611 (Improper Restriction of XML External Entity Reference) and can be categorized under ATT&CK technique T1190 (Exploit Public-Facing Application) when exploited through exposed management interfaces. Additional defensive measures should include implementing web application firewalls, monitoring for suspicious XML content in system logs, and conducting regular security assessments of API management and identity infrastructure components. The remediation process requires careful attention to ensure that XML parsing configurations are properly hardened without disrupting legitimate system functionality, as the affected components are integral to enterprise API and identity management operations.