Bug ID 738789: ASM/XML family parser does not support us-ascii encoding when it appears in the document prolog

Last Modified: Jan 24, 2019

Bug Tracker

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

Known Affected Versions:
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, 12.1.3,,,,,,,

Fixed In:
14.1.0, 12.1.4

Opened: Jul 31, 2018
Severity: 3-Major


ASM blocks requests when a request payload is an xml document with a prolog line at the begging with encoding="us-ascii"


Blocked xml requests


- ASM provisioned - ASM policy attached to a virtual server - ASM handles xml traffic with encoding="us-ascii" (this is very unlikely, the common case is encoding="utf-8")


Remove xml profile from a url in asm policy or disable XML malformed document detection via asm policy blocking settings

Fix Information

xml parser is fixed and now allows encoding="us-ascii"

Behavior Change