Sessoin expiration failure in BIG-IP Advanced WAF and ASM

Published: 2021-04-29
Risk Low
Patch available YES
Number of vulnerabilities 1
Exploitation vector Local
Public exploit N/A
Vulnerable software
BIG-IP Advanced WAF
Client/Desktop applications / Antivirus software/Personal firewalls

Hardware solutions / Security hardware applicances

Vendor F5 Networks, Inc.

Security Bulletin

This security bulletin contains one low risk vulnerability.

1) Insufficient Session Expiration

EUVDB-ID: #VU52754

Risk: Low

CVSSv3.1: 5.6 [CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]


CWE-ID: CWE-613 - Insufficient Session Expiration

Exploit availability: No


The vulnerability allows an attacker to gain unauthorized access to the system.

The vulnerability exists due to insufficient session expiration issue, as the Advanced WAF and BIG-IP ASM systems may not properly support the Post-Redirect-Get (PRG) application flow implemented on a back-end web server. After users log out of an application or site, they may log in again by clicking the browser Back button a multiple times.

This issue occurs when all of the following conditions are met:

  • You enabled brute force protection in your security policy.
  • You configure your security policy to use Client Side Integrity (CSI) or CAPTCHA challenge for brute force protection.
  • You associated the security policy with the virtual server to protect the back-end web server with the PRG application flow.


Install updates from vendor's website.

Vulnerable software versions

BIG-IP Advanced WAF: 13.0.0 - 16.0.1

BIG-IP ASM: 13.0.0 - 16.0.1

CPE2.3 External links

Q & A

Can this vulnerability be exploited remotely?

No. The attacker should have physical access to the system in order to successfully exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.