CVE-2022-21679Network attack vector

Authorization bypass via mixed-version proxy configuration

Published Jan 19, 2022 · Updated Apr 23, 2025

Authorization bypass in Istio 1.12.0 through 1.12.1 allows remote attackers to reach protected services with crafted Host headers. The 1.12 control plane emits the new Envoy host-matching API for 1.11 proxies, causing hosts and notHosts conditions to match every Host value. Exposure requires mixed 1.12 and 1.11 control and data planes plus an affected authorization rule; successful requests bypass intended access controls.

CVSS severity6.8
Medium
EPSS probability1.07%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authorization bypass in Istio 1.12.0 through 1.12.1 allows remote attackers to reach protected services with crafted Host headers. The 1.12 control plane emits the new Envoy host-matching API for 1.11 proxies, causing hosts and notHosts conditions to match every Host value. Exposure requires mixed 1.12 and 1.11 control and data planes plus an affected authorization rule; successful requests bypass intended access controls.

The record

CVE
CVE-2022-21679
Published
Jan 19, 2022
Updated
Apr 23, 2025
Vendor
Istio
Product
Istio
Classifications
CWE-670
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 19, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 23, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 1.12.0, < 1.12.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Istio · Istioversion=>= 1.12.0, < 1.12.2

Published CVSS scores

6.8GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-670Always-Incorrect Control Flow Implementation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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