Vulnerability report

Exploited in the wild Confirmed confidence In CISA KEV

CVE-2022-23131

Frontend Authentication Bypass

Zabbix / Frontend · 5.4.0 - 5.4.8

Severity
CVSS 9.1 · Critical
Confidence
Confirmed
Exploit status
Exploited in the wild
EPSS
95.7%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2022-23131 is an unauthenticated vulnerability affecting Zabbix Frontend. In the case of instances where the SAML SSO authentication is enabled (non-default), session data can be modified by a malicious actor,...

Is it exploited?

Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is confirmed. Listed in CISA KEV. Also confirmed by third-party sources.

Who is affected?

Zabbix / Frontend 5.4.0 - 5.4.8.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

Frontend Authentication Bypass

In the case of instances where the SAML SSO authentication is enabled (non-default), session data can be modified by a malicious actor, because a user login stored in the session was not verified. Malicious unauthenticated actor may exploit this issue to escalate privileges and gain admin access to Zabbix Frontend.

To perform the attack, SAML authentication is required to be enabled and the actor has to know the username of Zabbix user (or use the guest account, which is disabled by default).

Zabbix Affected
Frontend
5.4.0 - 5.4.8
Zabbix Unaffected
Frontend
Before 5.4.9*
Published
13 Jan 2022
Exploitation Reported
22 Feb 2022
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

Tags

nuclei_scanner cisa

CVE References

Exploitation evidence

Why Previdian marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CISA

Recorded 22 Feb 2022

A trusted third party reported exploitation.

Proof of concept available

GitHub

Recorded 18 Feb 2022

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
CISA First 2022-02-22 00:00 UTC
The Shadowserver 2026-09-21 00:00 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
0
0
0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

9.1 Critical

Potential damage if exploited. Separate from whether attackers are using it.

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

EPSS

95.7%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

All CVSS Scores

CVSS v3.1 9.1 Critical

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

CVSS v2.0 5.1 Medium

AV:N/AC:H/Au:N/C:P/I:P/A:P

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

Timeline

From disclosure to observed exploitation

  1. 00:00 UTC

    KEV confirmed by The Shadowserver

    Exploitation attested by an external source

  2. 14:20 UTC

    Public PoC available

    Public proof-of-concept code published

  3. 00:00 UTC

    Nuclei template available

    Scanner coverage available

  4. 00:00 UTC

    Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  5. 15:50 UTC

    CVE published

    Vulnerability disclosed publicly

  6. 00:00 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2022-23131

Sample API response
{
  "cve_id": "CVE-2022-23131",
  "confidence": "Confirmed",
  "cvss_score": 9.1,
  "cvss_estimated": false,
  "epss_score": 0.95683,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}