CVE-2019-25101 in TurboGears
Summary
by MITRE • 02/04/2023
A vulnerability classified as critical has been found in OnShift TurboGears 1.0.11.10. This affects an unknown part of the file turbogears/controllers.py of the component HTTP Header Handler. The manipulation leads to http response splitting. It is possible to initiate the attack remotely. Upgrading to version 1.0.11.11 is able to address this issue. The name of the patch is f68bbaba47f4474e1da553aa51564a73e1d92a84. It is recommended to upgrade the affected component. The associated identifier of this vulnerability is VDB-220059.
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Analysis
by VulDB Data Team • 03/04/2023
This critical vulnerability in OnShift TurboGears 1.0.11.10 resides within the HTTP Header Handler component, specifically in the turbogears/controllers.py file where improper input validation allows for HTTP response splitting attacks. The flaw occurs when user-supplied data containing newline characters is directly incorporated into HTTP response headers without adequate sanitization or encoding, creating a pathway for attackers to inject malicious content into HTTP responses. This vulnerability is classified under CWE-113 as "Improper Neutralization of CRLF Characters in HTTP Headers" and represents a significant security risk that can be exploited remotely without requiring authentication or specialized privileges. The attack vector leverages the fundamental weakness in how the application processes and handles HTTP headers, making it particularly dangerous in web applications where header manipulation can lead to various downstream security issues.
The operational impact of this HTTP response splitting vulnerability extends beyond simple header injection, as it can enable sophisticated attack patterns such as cross-site scripting attacks, session hijacking, and cache poisoning. When an attacker successfully splits an HTTP response, they can inject additional headers or content that will be processed by web browsers or intermediate proxies, potentially redirecting users to malicious sites or injecting malicious scripts into web pages. This vulnerability directly maps to ATT&CK technique T1190 "Exploit Public-Facing Application" and can be leveraged as part of broader attack chains targeting web application security. The vulnerability's remote exploitability means that attackers can trigger the condition through standard web requests without needing physical access to the target system, making it particularly dangerous in publicly accessible web applications.
The remediation strategy focuses on upgrading to version 1.0.11.11, which includes the patch identified by commit hash f68bbaba47f4474e1da553aa51564a73e1d92a84. This patch implements proper input validation and sanitization of HTTP header values, ensuring that newline characters and other potentially dangerous sequences are properly escaped or removed before being incorporated into HTTP responses. Organizations should also implement additional defensive measures including web application firewalls, input validation at multiple layers, and comprehensive security testing of HTTP header handling components. The vulnerability demonstrates the critical importance of proper input sanitization in web applications and highlights the need for regular security updates and vulnerability assessments to maintain robust security postures against evolving threat landscapes.