Yum fails with "Tunnel connection failed: 403 Forbidden" error

Issue

• Yum is unable to pull repos and throws a "Tunnel connection failed: 403 Forbidden" traceback in /var/log/rhsm/rhsm.log file.

 [ERROR] yum:3810:MainThread @repolib.py:364 - Tunnel connection failed: 403 Forbidden
Traceback (most recent call last):
  File "/usr/lib64/python2.7/site-packages/subscription_manager/repolib.py", line 361, in __init__
    self.override_supported = bool(self.identity.is_valid() and self.uep and self.uep.supports_resource('content_overrides'))
  File "/usr/lib64/python2.7/site-packages/rhsm/connection.py", line 894, in supports_resource
    self._load_supported_resources()
  File "/usr/lib64/python2.7/site-packages/rhsm/connection.py", line 881, in _load_supported_resources
    resources_list = self.conn.request_get("/")
  File "/usr/lib64/python2.7/site-packages/rhsm/connection.py", line 690, in request_get
    return self._request("GET", method, headers=headers)
  File "/usr/lib64/python2.7/site-packages/rhsm/connection.py", line 716, in _request
    info=info, headers=headers)
  File "/usr/lib64/python2.7/site-packages/rhsm/connection.py", line 555, in _request
    conn.request(request_type, handler, body=body, headers=final_headers)
  File "/usr/lib64/python2.7/httplib.py", line 1041, in request
    self._send_request(method, url, body, headers)
  File "/usr/lib64/python2.7/httplib.py", line 1075, in _send_request
    self.endheaders(body)
  File "/usr/lib64/python2.7/httplib.py", line 1037, in endheaders
    self._send_output(message_body)
  File "/usr/lib64/python2.7/httplib.py", line 881, in _send_output
    self.send(msg)
  File "/usr/lib64/python2.7/httplib.py", line 843, in send
    self.connect()
  File "/usr/lib64/python2.7/httplib.py", line 1251, in connect
    HTTPConnection.connect(self)
  File "/usr/lib64/python2.7/httplib.py", line 827, in connect
    self._tunnel()
  File "/usr/lib64/python2.7/httplib.py", line 809, in _tunnel
    message.strip()))
error: Tunnel connection failed: 403 Forbidden