Skip to content
Noroxi
NVD / CVE Program· CNA GitHub_M

CVE-2023-30851: Potential HTTP policy bypass when using header rules in Cilium

MediumCVSS 5.3 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 21/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.65% (FIRST EPSS); higher than 51.8% of all records.
  • Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: github.com/cilium/cilium (Go) 1.12.9, 1.13.2, 1.11.16.
  • Severity is disputed: the assigning authority (CNA) scores it 2.6, NVD 5.3.

Low priority for now. Upgrade to github.com/cilium/cilium (Go) 1.12.9, 1.13.2, 1.11.16 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. This issue only impacts users who have a HTTP policy that applies to multiple `toEndpoints` AND have an allow-all rule in place that affects only one of those endpoints. In such cases, a wildcard rule will be appended to the set of HTTP rules, which could cause bypass of HTTP policies. This issue has been patched in Cilium 1.11.16, 1.12.9, and 1.13.2.

Published
May 25, 2023
Updated
Jun 17, 2026
EPSS
0.6% · 51th percentile

Report tools

JSON

Action score

21

Monitor

Low priority for now.

CVSS
21 / 40 · 5.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.6%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
5.3
CNA · GitHub_M
2.6
2.7 point gap

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2023-30851

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits every 10 minutes on paid plans, on the hour on the free plan.

Your free account also gets you

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools, at most 30 a day (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for cilium records
Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

We use this product, ask for help

Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
ciliumcilium

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • cilium cilium

    • < 1.11.16, >= 1.12.0, < 1.12.9, >= 1.13.0, < 1.13.2affected

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • cilium ciliumbefore 1.11.16
  • cilium cilium1.12.0 and later · before 1.12.9
  • cilium cilium1.13.0 and later · before 1.13.2

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Gogithub.com/cilium/ciliumfrom 1.12.0 · before 1.12.91.12.9
Gogithub.com/cilium/ciliumfrom 1.13.0 · before 1.13.21.13.2
Gogithub.com/cilium/ciliumbefore 1.11.161.11.16

Same product

cilium: all records

Other highest-scoring records for the same primary product.

  • CVE-2023-27595Cilium eBPF filters may be temporarily removed during agent restart
    39Monitor
  • CVE-2023-39347Cilium NetworkPolicy bypass via pod labels
    36Monitor
  • CVE-2026-56742Cilium: Namespaced HTTPRoutes can redirect traffic to other namespaces
    35Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2023-27594Mar 17, 2023 · Cilium vulnerable to potential network policy bypass when routing IPv6 traffic
    29Monitor
  • ← EarlierCVE-2023-29002Apr 18, 2023 · Debug mode leaks confidential data in Cilium
    25Monitor
  • Later →CVE-2023-34242Jun 15, 2023 · Cilium vulnerable to information leakage via incorrect ReferenceGrant handling
    21Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Go:github.com/cilium/cilium1.11.16Package registry (OSV)
Go:github.com/cilium/cilium1.12.9Package registry (OSV)
Go:github.com/cilium/cilium1.13.2Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
high · data can be read
Integrity
none
Availability
none
Attack vector
Network
Attack complexity
High
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
None
Availability impact
None

Weakness class (CWE)

CWE-693 · Protection Mechanism Failure

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

References

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records