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Public proof of conceptFix available

CVE-2021-45468

A public proof of concept exists; no exploitation attested.

  • Published2022-01-14
  • Fixed in2021-12-23
  • WeaknessCWE-444

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2022-01-1418:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-11-03 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-45468?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-45468?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Imperva web application firewall
BranchAffectedFixed in
2021.x< 2021-12-232021-12-23

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

  1. Update Imperva web application firewall to 2021-12-23

Detection

read 2026-11-02 22:42 UTC
Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
1 repository, unverified0xhaggis/Imperva_gzip_bypass
PoC-in-GitHub
Metasploit modules
none listed
Metasploit Framework

Sources

  • NVDCVSS 3.19.8read 2026-10-23
  • NVDCVSS 2.07.5read 2026-10-23
  • NVDweakness (CWE)CWE-444read 2026-10-23
  • FIRST EPSSEPSS score4.0 %2026-11-03
  • PoC-in-GitHubproof of concept1read 2026-11-02

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published
2022-01-14
Last Modified
2026-06-17
NVD status
Modified

Frequently asked questions

What is 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.

Is CVE-2021-45468 actively exploited?

Active exploitation of CVE-2021-45468 has not been confirmed. Its EPSS score was 4.0% on 2026-11-03, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-45468?

CVE-2021-45468 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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Sources for this record