CVE-2006-1039 in Web Application Server
Summary
by MITRE
SAP Web Application Server (WebAS) Kernel before 7.0 allows remote attackers to inject arbitrary bytes into the HTTP response and obtain sensitive authentication information, or have other impacts, via a ";%20" followed by encoded HTTP headers.
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Analysis
by VulDB Data Team • 05/24/2025
The vulnerability described in CVE-2006-1039 affects SAP Web Application Server Kernel versions prior to 7.0, representing a critical security flaw that enables remote attackers to manipulate HTTP responses through carefully crafted input sequences. This vulnerability specifically targets the kernel's handling of HTTP headers and response construction mechanisms, creating an avenue for attackers to inject arbitrary bytes into HTTP responses. The flaw manifests when malicious input containing the sequence ";%20" followed by encoded HTTP headers is processed by the SAP WebAS kernel, allowing unauthorized manipulation of the response content.
The technical implementation of this vulnerability stems from inadequate input validation and sanitization within the SAP WebAS kernel's HTTP processing components. When the kernel encounters the specific pattern of ";%20" followed by encoded headers, it fails to properly sanitize or validate the input before incorporating it into the HTTP response. This improper handling creates a path for attackers to inject additional HTTP headers or modify existing ones, potentially enabling various malicious activities. The vulnerability aligns with CWE-1107, which addresses improper neutralization of special elements in HTTP headers, and demonstrates how insufficient input validation can lead to header injection attacks.
The operational impact of this vulnerability extends beyond simple header manipulation, as it can potentially expose sensitive authentication information to attackers. When successful, the injection of arbitrary bytes into HTTP responses allows threat actors to access session tokens, authentication cookies, or other sensitive data that might be transmitted within the HTTP response. This capability significantly increases the risk of unauthorized access to protected resources and could lead to complete system compromise if combined with other attack vectors. The vulnerability also enables other malicious impacts such as cross-site scripting attacks, cache poisoning, or redirection to malicious sites, making it particularly dangerous in enterprise environments where SAP systems handle sensitive business data.
Organizations running SAP Web Application Server Kernel versions before 7.0 should prioritize immediate remediation through official SAP security patches and updates. The recommended mitigation strategy involves upgrading to SAP WebAS Kernel version 7.0 or later, which includes enhanced input validation and sanitization mechanisms to prevent the injection of malicious HTTP header sequences. Additionally, network administrators should implement proper input filtering at proxy servers and web application firewalls to detect and block suspicious ";%20" sequences before they reach the vulnerable SAP systems. This vulnerability demonstrates the importance of adhering to secure coding practices and proper HTTP header handling as outlined in the ATT&CK framework's technique T1190 for exploiting HTTP headers. Organizations should also conduct thorough security assessments of their SAP environments to identify potential similar vulnerabilities and ensure comprehensive protection against header injection attacks that could compromise their enterprise applications.