Bug ID 677119: HTTP2 implementation incorrectly treats SETTINGS_MAX_HEADER_LIST_SIZE

Last Modified: Jun 30, 2021

Bug Tracker

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

Known Affected Versions:
11.6.0, 11.6.0 HF1, 11.6.0 HF2, 11.6.0 HF3, 11.6.0 HF4, 11.6.0 HF5, 11.6.0 HF6, 11.6.0 HF7, 11.6.0 HF8, 11.6.1, 11.6.1 HF1, 11.6.1 HF2, 11.6.2, 11.6.2 HF1, 11.6.3,, 12.0.0, 12.0.0 HF1, 12.0.0 HF2, 12.0.0 HF3, 12.0.0 HF4, 12.1.0, 12.1.0 HF1, 12.1.0 HF2, 12.1.1, 12.1.1 HF1, 12.1.1 HF2, 12.1.2, 12.1.2 HF1, 12.1.2 HF2, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3

Fixed In:
13.0.1, 12.1.3,

Opened: Aug 04, 2017
Severity: 3-Major


When HTTP2 connection's parameters are negotiated, either side may report about its limits in SETTINGS type frame where one of the parameters SETTINGS_MAX_HEADER_LIST_SIZE determines a maximum size of headers list it is willing to accept. The BIG-IP system incorrectly interchanged this parameter with another one called SETTINGS_HEADER_TABLE_SIZE, limiting value of the former one to 32,768.


The BIG-IP system does not accept the value, and terminates the connection using GOAWAY frame with PROTOCOL_ERROR as a reason.


HTTP2 is configured and an opposite endpoint (user agent using HTTP2 protocol) tries to set SETTINGS_MAX_HEADER_LIST_SIZE to a value above 32,768.



Fix Information

The BIG-IP system no longer generates an error due to this issue, and allows value for SETTINGS_MAX_HEADER_LIST_SIZE to exceed 32,768.

Behavior Change