CVE-2018-2504 in NetWeaver AS JAVA
Summary
by MITRE
SAP NetWeaver AS Java Web Container service does not validate against whitelist the HTTP host header which can result in HTTP Host Header Manipulation or Cross-Site Scripting (XSS) vulnerability. This is fixed in versions 7.10, 7.11, 7.20, 7.30, 7.31, 7.40, 7.50.
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Analysis
by VulDB Data Team • 04/20/2020
The vulnerability identified as CVE-2018-2504 affects SAP NetWeaver Application Server Java Web Container service, representing a critical security flaw in the HTTP host header validation mechanism. This issue stems from the absence of proper whitelist validation for HTTP host headers within the web container service, creating a pathway for malicious actors to manipulate host header values in HTTP requests. The vulnerability specifically targets the Java-based web container component that processes incoming HTTP requests and generates responses, making it a fundamental component of the application server's security architecture.
The technical flaw manifests when the web container fails to validate incoming HTTP host headers against a predefined whitelist of acceptable values, allowing attackers to inject arbitrary host header values into HTTP requests. This lack of validation creates multiple attack vectors including host header manipulation that can be exploited to perform various malicious activities. The vulnerability directly maps to CWE-20: Improper Input Validation, specifically targeting the validation of HTTP headers within web applications. The flaw enables attackers to manipulate the host header value in ways that can bypass security controls and potentially redirect users to malicious sites.
The operational impact of this vulnerability extends beyond simple header manipulation, as it opens the door to more sophisticated attacks including cross-site scripting exploits and host header injection attacks. When an attacker successfully manipulates the host header, they can potentially redirect users to malicious domains, inject malicious content into web responses, or bypass authentication mechanisms that rely on host header validation. This vulnerability particularly affects applications that use the host header for session management, authentication, or URL generation, making it a significant concern for enterprise web applications. The attack surface is broad as it affects any application running on SAP NetWeaver AS Java that processes HTTP requests through the affected web container service.
The remediation for CVE-2018-2504 requires implementing proper host header validation mechanisms within the SAP NetWeaver AS Java Web Container service. Organizations should upgrade to the fixed versions 7.10, 7.11, 7.20, 7.30, 7.31, 7.40, and 7.50, which contain the necessary patches to enforce proper whitelist validation for HTTP host headers. Security controls should be implemented to validate host headers against a strict whitelist of approved values, ensuring that only legitimate host names are accepted. This approach aligns with the ATT&CK technique T1071.004 for Application Layer Protocol: DNS and follows security best practices for preventing host header injection attacks. Organizations should also implement proper input validation controls and regularly audit their web application configurations to ensure that host header validation is properly enforced. The vulnerability demonstrates the critical importance of validating all user-supplied input, particularly HTTP headers, and implementing robust security controls at the application layer to prevent manipulation of core web application components.