CVE-2023-27594: Github.com/cilium/cilium Potential Network Policy Bypass When Vulnerability

MODERATE
Advisory Identifier: GHSA-8fg8-jh2h-f2hc
CVSS 4.2
CWE-285 CWE-863
Published
Advisory Summary

CVE-2023-27594 is a MODERATE (CVSS 4.2) potential network policy bypass when vulnerability (CWE-285: Improper Authorization) affecting Github.com/cilium/cilium libraries in the Go ecosystem. The issue involves potential network policy bypass when routing ipv6 traffic. Remediation is available by upgrading affected packages to version 1.11.15, 1.12.8, 1.13.1.

CVE-2023-27594 at a Glance

CVE Identifier CVE-2023-27594
GHSA Identifier GHSA-8fg8-jh2h-f2hc
Severity MODERATE
CVSS v3.1 Base Score 4.2
CWE Classification CWE-285: Improper Authorization
Affected Product Github.com/cilium/cilium
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 4.2

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N).

Attack Vector Adjacent (AV:A)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2023-27594

To remediate this vulnerability, upgrade all affected Github.com/cilium/cilium dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/cilium/cilium fixed: 1.11.15
Upgrade github.com/cilium/cilium to 1.11.15
github.com/cilium/cilium fixed: 1.12.8
Upgrade github.com/cilium/cilium to 1.12.8
github.com/cilium/cilium fixed: 1.13.1
Upgrade github.com/cilium/cilium to 1.13.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

inspect dependencies for github.com/cilium/cilium

How to Check if You Are Affected

To determine whether your application is affected by CVE-2023-27594, inspect your project dependencies for Github.com/cilium/cilium:

inspect dependencies for github.com/cilium/cilium

Analyze the terminal output to locate any version of Github.com/cilium/cilium in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.11.15), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-285: Improper Authorization, where the product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. In Github.com/cilium/cilium, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

## Impact Under specific conditions, Cilium may misattribute the source IP address of traffic to a cluster, identifying external traffic as coming from the host on which Cilium is running. As a consequence, network policies for that cluster might be bypassed, depending on the specific network policies enabled. Only IPv6 traffic is impacted by this vulnerability. This issue only manifests when: * Cilium is routing IPv6 traffic, and * Kube-proxy is used for service handling, and * NodePorts are used to route traffic to pods. IPv6 is disabled by default. Cilium's kube-proxy replacement feature is not affected by this vulnerability. ## Patches The problem has been fixed and is available on versions >=1.11.15, >=1.12.8, >=1.13.1 ## Workarounds Disable IPv6 routing (IPv6 is disabled by default). ## Acknowledgements The Cilium community has worked together with members of Isovalent to prepare these mitigations. Special thanks to Yusuke Suzuki for both highlighting and fixing the issue. ## For more information If you have any questions or comments about this advisory, please reach out on [Slack](https://docs.cilium.io/en/latest/community/community/#slack). As usual, if you think you found a related vulnerability, we strongly encourage you to report security vulnerabilities to our private security mailing list: security@cilium.io - first, before disclosing them in any public forums. This is a private mailing list where only members of the Cilium internal security team are subscribed to, and is treated as top priority.

CVE-2023-27594 Affected Github.com/cilium/cilium Versions

3 component(s)
Fixed Versions:
1.11.151.12.81.13.1
Product / Package Ecosystem Affected Versions Fixed Version
github.com/cilium/cilium
Go
< 1.11.15
1.11.15
github.com/cilium/cilium
Go
≥ 1.12.0
< 1.12.8
1.12.8
github.com/cilium/cilium
Go
≥ 1.13.0
< 1.13.1
1.13.1

References

Frequently Asked Questions

What is CVE-2023-27594?
CVE-2023-27594 is a security vulnerability in Github.com/cilium/cilium involving Potential network policy bypass when routing IPv6 traffic under CWE-285: Improper Authorization.
Which Github.com/cilium/cilium versions are affected?
Affected versions include releases prior to 1.11.15, 1.12.8, 1.13.1 across affected packages: github.com/cilium/cilium.
What version fixes CVE-2023-27594?
Upgrading to 1.11.15, 1.12.8, 1.13.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/cilium/cilium affected?
Yes, github.com/cilium/cilium is affected in releases prior to 1.11.15, 1.12.8, 1.13.1. Upgrade your dependency to 1.11.15, 1.12.8, 1.13.1 or later.
What is the CVSS score of CVE-2023-27594?
CVE-2023-27594 has a CVSS v3.1 base score of 4.2 (MODERATE) with vector string CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N.
What CWE is associated with CVE-2023-27594?
CVE-2023-27594 is classified under CWE-285: Improper Authorization (The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.).
How can I check Go dependencies for CVE-2023-27594?
Run the dependency tree command: 'inspect dependencies for github.com/cilium/cilium'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-8fg8-jh2h-f2hc",
  "modified" : "2023-03-17T21:38:38Z",
  "published" : "2023-03-17T18:22:19Z",
  "aliases" : [ "CVE-2023-27594" ],
  "summary" : "Potential network policy bypass when routing IPv6 traffic ",
  "details" : "## Impact\n\nUnder specific conditions, Cilium may misattribute the source IP address of traffic to a cluster, identifying external traffic as coming from the host on which Cilium is running. As a consequence, network policies for that cluster might be bypassed, depending on the specific network policies enabled. Only IPv6 traffic is impacted by this vulnerability.\n\nThis issue only manifests when:\n* Cilium is routing IPv6 traffic, and\n* Kube-proxy is used for service handling, and\n* NodePorts are used to route traffic to pods.\n\nIPv6 is disabled by default. Cilium's kube-proxy replacement feature is not affected by this vulnerability.\n\n## Patches\n\nThe problem has been fixed and is available on versions >=1.11.15, >=1.12.8, >=1.13.1\n\n## Workarounds\n\nDisable IPv6 routing (IPv6 is disabled by default).\n\n## Acknowledgements\n\nThe Cilium community has worked together with members of Isovalent to prepare these mitigations. Special thanks to Yusuke Suzuki for both highlighting and fixing the issue.\n\n## For more information\n\nIf you have any questions or comments about this advisory, please reach out on [Slack](https://docs.cilium.io/en/latest/community/community/#slack).\n\nAs usual, if you think you found a related vulnerability, we strongly encourage you to report security vulnerabilities to our private security mailing list: security@cilium.io - first, before disclosing them in any public forums. This is a private mailing list where only members of the Cilium internal security team are subscribed to, and is treated as top priority.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/cilium/cilium"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.11.15"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/cilium/cilium"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.12.0"
      }, {
        "fixed" : "1.12.8"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/cilium/cilium"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.13.0"
      }, {
        "fixed" : "1.13.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/cilium/cilium/security/advisories/GHSA-8fg8-jh2h-f2hc"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2023-27594"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/cilium/cilium"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/cilium/cilium/releases/tag/v1.11.15"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/cilium/cilium/releases/tag/v1.12.8"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/cilium/cilium/releases/tag/v1.13.1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-285", "CWE-863" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-03-17T18:22:19Z",
    "nvd_published_at" : "2023-03-17T20:15:00Z"
  }
}