CVE-2018-1905 in WebSphere Application Server
Summary
by MITRE
IBM WebSphere Application Server 9.0.0.0 through 9.0.0.9 is vulnerable to a XML External Entity Injection (XXE) attack when processing XML data. A remote attacker could exploit this vulnerability to expose sensitive information or consume memory resources. IBM X-Force ID: 152534.
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Analysis
by VulDB Data Team • 06/11/2023
IBM WebSphere Application Server versions 9.0.0.0 through 9.0.0.9 contain a critical XML External Entity Injection vulnerability that represents a significant security weakness in enterprise application infrastructure. This vulnerability falls under the CWE-611 category of XML External Entity Processing and aligns with ATT&CK technique T1213.002 for Data from Information Repositories, as it enables unauthorized access to sensitive system information through malformed XML processing. The flaw occurs when the application server processes XML data without proper validation or sanitization of external entity references, creating an attack surface that allows malicious actors to manipulate the XML parser behavior.
The technical implementation of this vulnerability stems from the server's insufficient input validation mechanisms when handling XML payloads. When processing XML documents that contain external entity declarations, the system fails to properly restrict or disable external entity resolution, allowing attackers to craft malicious XML requests that can reference external resources. This misconfiguration enables attackers to perform various malicious activities including information disclosure through entity expansion, denial of service via memory exhaustion attacks, and potentially unauthorized data access. The vulnerability specifically affects the XML processing components within the WebSphere Application Server runtime environment where XML data is parsed and interpreted.
Operational impact of this vulnerability extends beyond simple information disclosure to encompass significant system resource consumption and potential service disruption. Attackers can exploit the XXE vulnerability to perform memory exhaustion attacks by creating recursive entity references that consume excessive system resources, leading to denial of service conditions that can impact business-critical applications. The vulnerability also enables unauthorized access to internal system information, potentially exposing sensitive data through entity expansion techniques that can retrieve local files or internal network resources. Organizations running affected WebSphere versions face risks of data breaches, service interruptions, and compliance violations that could result in substantial financial and reputational damage.
Mitigation strategies for this vulnerability should include immediate application of IBM's security patches and updates, which address the root cause by implementing proper XML parser configurations that disable external entity resolution. Organizations should also implement network-level controls including firewall rules that restrict access to XML processing endpoints and deploy XML validation mechanisms that sanitize incoming XML data before processing. The implementation of proper input validation and sanitization procedures, combined with regular security assessments and monitoring of XML processing activities, can significantly reduce the attack surface. Additionally, organizations should consider implementing application firewalls or API gateways that can detect and block suspicious XML patterns, aligning with ATT&CK mitigation techniques that focus on preventing data exfiltration and unauthorized access to system resources.