remove rc4 from the default client ciphers (closes #23481)

Lib/ssl.py

@@ -157,14 +157,12 @@ else:
 #   * Prefer any AES-GCM over any AES-CBC for better performance and security
 #   * Then Use HIGH cipher suites as a fallback
 #   * Then Use 3DES as fallback which is secure but slow
-#   * Finally use RC4 as a fallback which is problematic but needed for
-#     compatibility some times.
 #   * Disable NULL authentication, NULL encryption, and MD5 MACs for security
 #     reasons
 _DEFAULT_CIPHERS = (
     'ECDH+AESGCM:DH+AESGCM:ECDH+AES256:DH+AES256:ECDH+AES128:DH+AES:ECDH+HIGH:'
-    'DH+HIGH:ECDH+3DES:DH+3DES:RSA+AESGCM:RSA+AES:RSA+HIGH:RSA+3DES:ECDH+RC4:'
-    'DH+RC4:RSA+RC4:!aNULL:!eNULL:!MD5'
+    'DH+HIGH:ECDH+3DES:DH+3DES:RSA+AESGCM:RSA+AES:RSA+HIGH:RSA+3DES:!aNULL:'
+    '!eNULL:!MD5'
 )
 
 # Restricted and more secure ciphers for the server side

Misc/NEWS

@@ -21,6 +21,8 @@ Library
 - Issue #22885: Fixed arbitrary code execution vulnerability in the dumbdbm
   module.  Original patch by Claudiu Popa.
 
+- Issue #23481: Remove RC4 from the SSL module's default cipher list.
+
 - Issue #21849: Fixed xmlrpclib serialization of non-ASCII unicode strings in
   the multiprocessing module.