Bug ID 754109: ASM/Bot-Defense/DoSL7 content-security-policy header modification violates Content Security Policy directive

Last Modified: Nov 13, 2019

Bug Tracker

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

Known Affected Versions:
13.1.0, 13.1.0.1, 13.1.0.2, 13.1.0.3, 13.1.0.4, 13.1.0.5, 13.1.0.6, 13.1.0.7, 13.1.0.8, 13.1.1, 13.1.1.1, 13.1.1.2, 13.1.1.3, 13.1.1.4, 13.1.1.5, 13.1.3, 13.1.3.1, 14.0.0, 14.0.0.1, 14.0.0.2, 14.0.0.3, 14.0.0.4, 14.0.0.5, 14.0.1, 14.0.1.1, 14.1.0, 14.1.0.1, 14.1.0.2, 14.1.0.3, 14.1.0.4, 14.1.0.5, 14.1.0.6, 14.1.2, 14.1.2.1

Fixed In:
15.0.0

Opened: Dec 26, 2018
Severity: 2-Critical

Symptoms

When the backend server sends a content-security-policy header where source-src and default-src directives are missing, ASM will modify the header when it does its own JavaScript injection, which might cause a csp policy violation for inline JavaScript code.

Impact

Inline JavaScript does not run. The Browser reports a content-security-policy violation.

Conditions

-- ASM provisioned. -- ASM or Bot-Defense/DoS attached on a virtual server. -- ASM or Bot/Dos does inline injections, like CSRF/CSHUI.

Workaround

You can use either of the following workarounds: -- Disable csp in ASM by running the following commands: /usr/share/ts/bin/add_del_internal add csp_enabled 0 bigstart restart asm -- Disable csp in Bot/DoS using an iRule: when HTTP_REQUEST { set csp 0 } when HTTP_RESPONSE { if { [HTTP::header exists Content-Security-Policy] } { set csp "[HTTP::header values Content-Security-Policy]" } } when HTTP_RESPONSE_RELEASE { if { $csp != 0 } { HTTP::header replace Content-Security-Policy $csp } set csp 0 }

Fix Information

ASM/Bot/DoSL7 no longer modifies the csp header when both source-src and default-src directives are missing.

Behavior Change