F5 BIG-IP Cookie Information Disclosure Vulnerability

The most common reason for that compliance failure is due to use of default cookie-based BigIP persistency profile. By default, the cookie value is not encrypted.

Create a custom Cookie Persistency Profile (Local Traffic, Profiles:Persistence, New Persistence Profile)

Persistence Type: Cookie
Parent Profile: cookie

Configuration: Keep everything as default, except for two settings:

1 - Cookie Encryption Use Policy
Select tickbox to apply custom config, Select 'Required'
2 - Encryption Passphrase:
Select tickbox to apply custom config, enter an Encryption Passphrase

When done, go apply this new Persistency Profile to your Virtual Server. The relevant setting can be found in Virtual Server Resources tab.

Note that this change comes with a high risk of impact. Implement in PROD during a non-peak hour, verify if it works as intended in QA/test environment beforehand (if possible). If some customers complain that their sessions get repeatedly disconnected, the fix is to close, and re-open the Web-browser. If you want to mitigate the risk of impact, you can select 'Preferred' as the Encryption Policy instead of Required, this will allow encrypted and non-encrypted persistency cookies. However, note that this Encryption Policy may not suffice to mitigate your vulnerability.

Regards,