CVE-2021-45468

Name: CVE-2021-45468
Creator: NVD / NIST
Published: 2022-01-14T18:15:10.203+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 3.99%

Last modified Jun 17, 2026

CVE-2021-45468 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. Imperva Web Application Firewall (WAF) before 2021-12-23 allows remote unauthenticated attackers to use "Content-Encoding: gzip" to evade WAF security controls and send malicious HTTP POST requests to web servers behind the WAF.. EPSS estimates a 3.99% chance of exploitation in the next 30 days.

Description

Imperva Web Application Firewall (WAF) before 2021-12-23 allows remote unauthenticated attackers to use "Content-Encoding: gzip" to evade WAF security controls and send malicious HTTP POST requests to web servers behind the WAF.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

3.99%

89.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-444

Affected Software

Vendor	Product	Versions
Imperva	Web Application Firewall	< 2021-12-23

References

https://bishopfox.com/blog/imperva-eliminates-critical-exposureExploit, Third Party Advisory
https://bishopfox.com/blog/imperva-eliminates-critical-exposureExploit, Third Party Advisory

Timeline

Published: Jan 14, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-45468?

How severe is CVE-2021-45468?

CVE-2021-45468 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 3.99% probability of exploitation in the next 30 days.

How do I fix CVE-2021-45468?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-45468?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST