File CVE-2025-15367-poplib-ctrl-chars.patch of Package python3.42753

From b6f733b285b1c4f27dacb5c2e1f292c914e8b933 Mon Sep 17 00:00:00 2001
From: Seth Michael Larson <seth@python.org>
Date: Fri, 16 Jan 2026 10:54:09 -0600
Subject: [PATCH 1/2] Add 'test.support' fixture for C0 control characters

---
 Lib/poplib.py                                                            |    2 ++
 Lib/test/test_poplib.py                                                  |    8 ++++++++
 Misc/NEWS.d/next/Security/2026-01-16-11-43-47.gh-issue-143923.DuytMe.rst |    1 +
 3 files changed, 11 insertions(+)

Index: Python-3.6.15/Lib/poplib.py
===================================================================
--- Python-3.6.15.orig/Lib/poplib.py	2026-02-12 11:54:19.122320050 +0100
+++ Python-3.6.15/Lib/poplib.py	2026-02-12 12:56:30.246211101 +0100
@@ -117,6 +117,8 @@
     def _putcmd(self, line):
         if self._debugging: print('*cmd*', repr(line))
         line = bytes(line, self.encoding)
+        if re.search(b'[\x00-\x1F\x7F]', line):
+            raise ValueError('Control characters not allowed in commands')
         self._putline(line)
 
 
Index: Python-3.6.15/Lib/test/test_poplib.py
===================================================================
--- Python-3.6.15.orig/Lib/test/test_poplib.py	2026-02-12 11:54:17.550747411 +0100
+++ Python-3.6.15/Lib/test/test_poplib.py	2026-02-12 12:57:09.847479156 +0100
@@ -12,6 +12,7 @@
 
 from unittest import TestCase, skipUnless
 from test import support as test_support
+from test.support import control_characters_c0
 threading = test_support.import_module('threading')
 
 HOST = test_support.HOST
@@ -349,6 +350,13 @@
         self.assertIsNone(self.client.sock)
         self.assertIsNone(self.client.file)
 
+    def test_control_characters(self):
+        for c0 in control_characters_c0():
+            with self.assertRaises(ValueError):
+                self.client.user(f'user{c0}')
+            with self.assertRaises(ValueError):
+                self.client.pass_(f'{c0}pass')
+
     @requires_ssl
     def test_stls_capa(self):
         capa = self.client.capa()
Index: Python-3.6.15/Misc/NEWS.d/next/Security/2026-01-16-11-43-47.gh-issue-143923.DuytMe.rst
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ Python-3.6.15/Misc/NEWS.d/next/Security/2026-01-16-11-43-47.gh-issue-143923.DuytMe.rst	2026-02-12 12:56:30.247057377 +0100
@@ -0,0 +1 @@
+Reject control characters in POP3 commands.