Vulnerability in Imperva Web Application Firewall

CVE-2021-45468

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.

Vulnerability class: HTTP Request Smuggling

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.040 (90.2th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 90th percentile — 90.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2021-45468: held from 0.040 to 0.040.

EPSS over last 30 days · oldest: 0.040 · newest: 0.040 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-45468?
CVE-2021-45468 is a critical-severity vulnerability in Imperva Web Application Firewall, classified under Inconsistent Interpretation of HTTP Requests (HTTP Request/Response Smuggling). CVSS score: 9.8/10. Published 2022-01-14.
How severe is CVE-2021-45468?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2021-45468 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.