CVE-2020-8843Network attack vector

Policy bypass via trusted ingress attribute header

Published Feb 14, 2020 · Updated Aug 4, 2024

Improper input validation in Istio 1.3 through 1.3.6 allows remote attackers to bypass certain Mixer policies via a crafted header. The ingress proxy trusts an attacker-supplied x-istio-attributes value and uses its encoded source.uid when Mixer evaluates source-based policy. Exposure requires Mixer Policy to be enabled and selectively applied to a source equal to ingress; the feature is disabled by default.

CVSS severity7.4
High
EPSS probability1.06%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Istio 1.3 through 1.3.6 allows remote attackers to bypass certain Mixer policies via a crafted header. The ingress proxy trusts an attacker-supplied x-istio-attributes value and uses its encoded source.uid when Mixer evaluates source-based policy. Exposure requires Mixer Policy to be enabled and selectively applied to a source equal to ingress; the feature is disabled by default.

The record

CVE
CVE-2020-8843
Published
Feb 14, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-20, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 14, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.4NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
5.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:N

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.

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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-20Improper Input Validation
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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