Bug ID 427725: TMM produces core files in access deployments

Last Modified: Oct 06, 2020

Bug Tracker

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

Known Affected Versions:
11.3.0, 11.4.0, 11.4.1

Fixed In:
11.5.0, 11.4.1 HF2, 11.4.0 HF4, 11.3.0 HF8

Opened: Aug 12, 2013
Severity: 3-Major
Related AskF5 Article:


TMM produces core files in access deployments.


Traffic disrupted while tmm restarts.


For this problem to occur, the following should be true: 1) An Access profile is attached to a virtual server. 2) The Access policy is started with a POST. 3) The request header size exceeds 16384 bytes, or the request body size exceeds 64000 bytes. When the above happens, a local buffer is written past its size resulting in a crash. Note that if both limits in (3) are exceeded, this crash is prevented due to a protection.


A potential workaround is to attach an iRule to an HTTP event that detects this condition and prevent this transaction from getting to the Access filter.

Fix Information

The protection against HTTP requests that exceeds the Access filter's limits has been corrected to reflect its intent. This prevents the crash.

Behavior Change