Python http.client HTTP Request Smuggling Fix via CR/LF Validation

Vulnerability Overview This vulnerability concerns the denial of CR/LF (Carriage Return/Line Feed) characters in HTTP tunnel request headers. Specifically, the flaw exists in the and methods of the module, which fail to properly validate and control the use of control characters when processing tunnel request headers, potentially leading to security issues. Scope of Impact Module: Methods: and Version: Python 3.11 Remediation 1. Code Modifications: - In the method, add checks for control characters in the tunnel hostname to ensure it does not contain any control characters. - In the method, add checks for control characters in tunnel request headers to ensure that neither header names nor values contain control characters. 2. Test Cases: - Multiple test cases were added to verify the rejection of control characters in tunnel hostnames and request headers. Proof of Concept (POC) Code The following code snippets represent the patched relevant code: Test Cases ```python Lib/test/test_httplib.py def test_invalid_tunnel_headers(self): cases = { ('Invalid\rName', 'ValidValue'), ('Invalid\rName', 'ValidValue'), ('Invalid\rName', 'ValidValue'), ('\rInvalidName', 'ValidValue'), ('ValidName', '\rInvalidValue'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'InvalidValue\r'), ('ValidName', 'In

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Python http.client HTTP Request Smuggling Fix via CR/LF Validation

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