CVE-2021-23926 in SOA Suite
Summary
by MITRE • 01/14/2021
The XML parsers used by XMLBeans up to version 2.6.0 did not set the properties needed to protect the user from malicious XML input. Vulnerabilities include possibilities for XML Entity Expansion attacks. Affects XMLBeans up to and including v2.6.0.
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Analysis
by VulDB Data Team • 01/25/2026
The vulnerability identified as CVE-2021-23926 represents a critical security flaw in Apache XMLBeans version 2.6.0 and earlier, where the XML parsers fail to properly configure security settings to prevent malicious XML input processing. This weakness stems from insufficient protection mechanisms within the XML parsing framework, leaving applications that rely on XMLBeans susceptible to various XML-based attacks. The vulnerability specifically affects the XML Entity Expansion (XXE) attack surface, which is a well-documented class of security issues that can be exploited to cause denial of service, information disclosure, or even remote code execution depending on the implementation context.
The technical flaw manifests in the XML parser configuration where essential security properties are not enabled by default, particularly those related to disabling external entity resolution and limiting the expansion of XML entities. This configuration oversight allows attackers to craft malicious XML documents that can trigger excessive resource consumption through entity expansion, potentially leading to denial of service conditions. The vulnerability operates at the parser level, meaning any application using XMLBeans to process XML input is at risk regardless of the application's own security measures. This type of vulnerability maps directly to CWE-611 (Improper Restriction of XML External Entity Reference) and aligns with ATT&CK technique T1210 (Exploitation of Remote Services) when leveraged for denial of service or information disclosure attacks.
The operational impact of CVE-2021-23926 extends beyond simple parsing functionality, as it fundamentally compromises the security posture of systems that process XML data. Applications using XMLBeans for data ingestion, configuration management, or web service communication become vulnerable to attacks that can consume excessive system resources, potentially leading to system crashes or resource exhaustion. The vulnerability is particularly concerning in enterprise environments where XML processing is common for integration purposes, as it can affect multiple applications and services that depend on XMLBeans for data handling. Organizations may experience cascading effects where a single vulnerable component can compromise entire application stacks that process XML content, making this vulnerability particularly dangerous in complex enterprise architectures.
Mitigation strategies for CVE-2021-23926 should prioritize immediate upgrades to XMLBeans version 2.6.1 or later, which includes the necessary security patches to properly configure XML parser settings. System administrators should also implement additional protective measures such as disabling external entity resolution in XML parsers, implementing proper input validation and sanitization, and establishing network-level restrictions to prevent unauthorized XML data processing. Organizations should conduct thorough vulnerability assessments to identify all systems using affected XMLBeans versions and implement comprehensive monitoring to detect potential exploitation attempts. The remediation process should also include security awareness training for development teams to ensure proper XML processing security configurations are implemented in future applications. Additionally, implementing web application firewalls and XML-specific security controls can provide additional layers of protection while awaiting full patch deployment across all affected systems.