CVE-2006-6699 in Application Server Portal
Summary
by MITRE
Multiple CRLF injection vulnerabilities in Oracle Portal 9.0.2 and possibly other versions allow remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via CRLF sequences in the enc parameter to (1) calendarDialog.jsp or (2) fred.jsp. NOTE: the calendar.jsp vector is covered by CVE-2006-6697.
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Analysis
by VulDB Data Team • 07/13/2019
The vulnerability described in CVE-2006-6699 represents a critical security flaw in Oracle Portal 9.0.2 and potentially other versions that enables remote attackers to perform CRLF (Carriage Return Line Feed) injection attacks. This vulnerability specifically affects two.jsp files within the Oracle Portal application, namely calendarDialog.jsp and fred.jsp, where the enc parameter is susceptible to manipulation through CRLF sequences. The flaw stems from inadequate input validation and sanitization of user-supplied data, particularly within the web application's parameter handling mechanisms.
CRLF injection attacks exploit the fundamental structure of HTTP protocols by inserting carriage return and line feed characters into HTTP headers, which can lead to severe consequences including HTTP response splitting. When an attacker successfully injects CRLF sequences into the enc parameter, they can manipulate the HTTP response headers that the application generates, potentially allowing them to inject malicious headers or even create entirely separate HTTP responses. This technique enables attackers to bypass security controls, conduct session hijacking, or perform cache poisoning attacks. The vulnerability falls under the CWE-113 category for Improper Neutralization of CRLF Sequences in HTTP Headers, which is classified as a critical weakness in web applications. The attack vector specifically targets the HTTP header injection mechanism through the application's parameter processing, making it particularly dangerous in enterprise web environments where Oracle Portal serves as a central application platform.
The operational impact of this vulnerability extends beyond simple header injection, as HTTP response splitting can enable sophisticated attacks such as cross-site scripting exploitation, session fixation, or cache poisoning. Attackers can leverage this vulnerability to manipulate web cache servers, redirect users to malicious sites, or inject content that appears to originate from legitimate sources. The fact that this vulnerability affects Oracle Portal 9.0.2 suggests it exists in a version that was widely deployed in enterprise environments, making the potential impact significant. The vulnerability's presence in multiple.jsp files indicates a systemic issue within the application's parameter handling architecture, where the same input validation flaw exists across different application components. This type of vulnerability is particularly concerning in the context of the ATT&CK framework's web application attacks, as it can be used to establish initial access points for more complex attack chains.
Mitigation strategies for this vulnerability require immediate implementation of input validation and sanitization measures at the application level. Organizations should implement strict validation of all user-supplied input, particularly parameters that are directly used in HTTP header generation. The recommended approach involves filtering or encoding CRLF characters in all user inputs before processing, ensuring that these sequences cannot be embedded in HTTP headers. Additionally, implementing proper output encoding mechanisms and using web application firewalls can provide additional layers of protection against such attacks. The Oracle Portal administrators should also consider upgrading to patched versions of the software, as this vulnerability was likely addressed in subsequent releases. Security monitoring should include detection of suspicious CRLF sequences in HTTP headers, and access controls should be implemented to limit the exposure of vulnerable application components. Organizations should also conduct comprehensive security testing of their web applications to identify similar vulnerabilities in other parameters and application components, as this type of injection flaw often indicates broader architectural weaknesses in input handling.