CVE-2023-30851

HTTP policy bypass via wildcard rule insertion

Published May 25, 2023 · Updated Jan 16, 2025

HTTP policy bypass in affected Cilium releases allows remote authenticated users to read HTTP data blocked by configured rules. HTTP rule assembly appends a wildcard rule when one rule targets multiple endpoints and only one endpoint has an allow-all rule. Exploitation requires that specific policy combination and elevated cluster access, and it exposes only traffic that the intended HTTP rules would deny.

CVSS severity2.6
Low
EPSS probability0.66%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

HTTP policy bypass in affected Cilium releases allows remote authenticated users to read HTTP data blocked by configured rules. HTTP rule assembly appends a wildcard rule when one rule targets multiple endpoints and only one endpoint has an allow-all rule. Exploitation requires that specific policy combination and elevated cluster access, and it exposes only traffic that the intended HTTP rules would deny.

The record

CVE
CVE-2023-30851
Published
May 25, 2023
Updated
Jan 16, 2025
Vendor
Cilium
Product
Cilium
Classifications
CWE-693
Attack vector
adjacent
Privileges
admin

Timeline

How it unfolded

  1. May 25, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 16, 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=< 1.11.16
  2. Affected versionversion=>= 1.12.0, < 1.12.9
  3. Affected versionversion=>= 1.13.0, < 1.13.2

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesadmin

What is affected?

Cilium · Ciliumversion=< 1.11.16; version=>= 1.12.0, < 1.12.9; version=>= 1.13.0, < 1.13.2

Published CVSS scores

5.3NIST NVDCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
2.6GitHub, Inc.CVSS:3.1/AV:A/AC:H/PR:H/UI:N/S:C/C:L/I:N/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.

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)
Vectoradjacent
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-693Protection Mechanism Failure

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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