Bug ID 984521: Accept-Encoding header is stripped by Bot Defense profile in case of incompatible file extension and a dot in the file name

Last Modified: Apr 24, 2024

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

Known Affected Versions:
14.1.0,,,,,, 14.1.2,,,,,,,,, 14.1.3,, 14.1.4,,,,,,, 14.1.5,,,,,, 15.0.0, 15.0.1,,,,, 15.1.0,,,,,, 15.1.1, 15.1.2,, 15.1.3,, 15.1.4,, 15.1.5,, 15.1.6,, 15.1.7, 15.1.8,,, 15.1.9,, 15.1.10,,,, 16.0.0,, 16.0.1,,, 16.1.0, 16.1.1, 16.1.2,,, 16.1.3,,,,,, 16.1.4,,,

Opened: Jan 17, 2021

Severity: 4-Minor


Bot Defense profile checks if a page is not an HTML page by checking the file extension (among other ways). In case the filename contains a dot (.) - the parsing is wrong and it is not detected as incompatible. As a result, the Accept-Encoding header is removed (to allow injection in the response).


Accept-Encoding header is removed, causing the server to not send a gzipped response.


-- Bot Defense profile is attached to s virtual server configured with any response injection (Device ID, Browser Verification, or Single Page Application). Request is sent to an incompatible file extension (one of gif,png,bmp,jpg,ico,css,mp3,mp4,mpg,avi,wmv,mov,3gp,fla,swf,js), and filename contains a dot (.).


Add this specific URL to sys db: dosl7.parse_html_excluded_urls

Fix Information


Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips