Bug ID 551315: HTTP's handling of early server response might cause NTLM authentication failure.

Last Modified: Oct 06, 2020

Bug Tracker

Affected Product:  See more info
BIG-IP LTM(all modules)

Known Affected Versions:

Fixed In:
10.2.4 HF13

Opened: Oct 07, 2015
Severity: 3-Major
Related AskF5 Article:


Using the HTTP filter, NTLM authentication might fail if an early server response is received.


User cannot upload attachment to backend server using NTLM auth.


Using TMOS v10.2.4 HF12: If the system is in the middle of sending the request body to server, and at this time the server responds (with the response header) without waiting for the entire request body to arrive, this is considered as an early server response.


None known.

Fix Information

This bug is present only in TMOS v10.2.4 HF12. The behavior is now the same as later versions of the software.

Behavior Change