Bug ID 918093: Access-Control-Allow-Origin header with trailing white spaces causes Portal Access CORS failure.

Last Modified: Jan 06, 2023

Bug Tracker

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

Known Affected Versions:
15.1.0, 15.1.0.1, 15.1.0.2, 15.1.0.3, 15.1.0.4, 15.1.0.5, 15.1.1, 15.1.2, 15.1.2.1, 15.1.3, 15.1.3.1, 15.1.4, 15.1.4.1, 15.1.5, 15.1.5.1, 15.1.6, 15.1.6.1, 15.1.7, 15.1.8, 15.1.8.1, 16.0.0, 16.0.0.1, 16.0.1, 16.0.1.1, 16.0.1.2

Fixed In:
16.1.0

Opened: Jun 16, 2020
Severity: 3-Major

Symptoms

'Access-Control-Allow-Origin' header value may contain trailing white spaces in very rare cases, for example: Access-Control-Allow-Origin: http://example.com \r\n In this case, Cross-Origin Resource Sharing (CORS) validation may fail if the 'Origin' header value contains the same value as that of 'Access_Control_Allow_Origin', but without trailing white spaces, for example: Origin: http://example.com\r\n If CORS validation fails, content on the browser gets blocked.

Impact

Web application content gets blocked on the browser when accessed through Portal Access.

Conditions

-- 'Origin' header and 'Access-Control-Allow-Origin' header values match except for the trailing white space. -- Using Portal Access to access the resource.

Workaround

Use an iRule to truncate trailing white space from 'Access-Control-Allow-Origin' headers.

Fix Information

Now, content does not get blocked if 'Origin' header and 'Access-Control-Allow-Origin' header values match except for trailing white space.

Behavior Change