Bug ID 666616: Some HTTP iRule commands should always return results as Tcl lists, but do not.

Last Modified: Nov 07, 2022

Affected Product(s):
BIG-IP LTM(all modules)

Known Affected Versions:
13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1

Fixed In:

Opened: May 25, 2017

Severity: 3-Major

Related Article: K82565029


The HTTP iRule commands behave differently if they return only a single result. They will return a Tcl string rather than a Tcl list containing a string.


A string is returned rather than a list. This may affect Tcl code that expects the result to be a list, leading to incorrect behavior.


One or more of the following HTTP iRule commands are used, and the conditions exist such that a single result is returned: HTTP::cookie names HTTP::cookie attribute names HTTP::header names HTTP::header values


If the result is not a list, this can be detected in a Tcl script, and the result handled as a special case.

Fix Information

HTTP iRule commands that return a Tcl list will do so in all cases.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips