Skip to content
Heist/ feed
Back to feed
Critical

Authentication bypass using an empty token in capsule-proxy

Type: advisorySources: OSV

capsule-proxy is a reverse proxy for the capsule operator project. Affected versions are subject to a privilege escalation vulnerability which is based on a missing check if the user is authenticated based on the `TokenReview` result. All the clusters running with the `anonymous-auth` Kubernetes API Server setting disable (set to `false`) are affected since it would be possible to bypass the token review mechanism, interacting with the upper Kubernetes API Server. This privilege escalation cannot be exploited if you're relying only on client certificates (SSL/TLS). This vulnerability has been addressed in version 0.4.6. Users are advised to upgrade.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2023-48312
Confirmed fixed CVEs
Not specified
Updated in this feed
7 Nov 2026, 02:28 UTC · Revision 1

Source evidence

Authentication bypass using an empty token in capsule-proxy

core-osv · Original source

Published 24 Nov 2023, 17:12 UTC

capsule-proxy is a reverse proxy for the capsule operator project. Affected versions are subject to a privilege escalation vulnerability which is based on a missing check if the user is authenticated based on the `TokenReview` result. All the clusters running with the `anonymous-auth` Kubernetes API Server setting disable (set to `false`) are affected since it would be possible to bypass the token review mechanism, interacting with the upper Kubernetes API Server. This privilege escalation cannot be exploited if you're relying only on client certificates (SSL/TLS). This vulnerability has been addressed in version 0.4.6. Users are advised to upgrade.

osv:CVE-2023-48312
Complete source record
{
  "id": "9369903c103c6b86b7ab10c2eeadee8c3b2f37d39b9a98a80f8502eb526168ca",
  "url": "https://osv.dev/vulnerability/CVE-2023-48312",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Authentication bypass using an empty token in capsule-proxy",
    "summary": "capsule-proxy is a reverse proxy for the capsule operator project. Affected versions are subject to a privilege escalation vulnerability which is based on a missing check if the user is authenticated based on the `TokenReview` result. All the clusters running with the `anonymous-auth` Kubernetes API Server setting disable (set to `false`) are affected since it would be possible to bypass the token review mechanism, interacting with the upper Kubernetes API Server. This privilege escalation cannot be exploited if you're relying only on client certificates (SSL/TLS). This vulnerability has been addressed in version 0.4.6. Users are advised to upgrade.",
    "evidence": "osv:CVE-2023-48312",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2023-48312",
      "aliases": [
        "CVE-2023-48312",
        "GHSA-fpvw-6m5v-hqfp",
        "GO-2023-2351"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/projectcapsule/capsule-proxy",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "472404f7006a4152e4eec76dee07324dd1e6e823"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:clastix:capsule-proxy:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "0.4.5"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "472404f7006a4152e4eec76dee07324dd1e6e823"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "helm-v0.5.0",
            "v0.4.5",
            "helm-v0.4.9",
            "v0.4.4",
            "v0.4.3",
            "v0.4.2",
            "helm-v0.4.3",
            "helm-v0.4.2",
            "v0.4.1",
            "helm-v0.4.1",
            "v0.4.0",
            "helm-v0.4.0",
            "helm-v0.3.7",
            "v0.3.3",
            "helm-v0.3.6",
            "helm-v0.3.5",
            "helm-v0.3.4",
            "v0.3.2",
            "helm-v0.3.3",
            "v0.3.1",
            "helm-v0.3.2",
            "v0.3.1-rc0",
            "v0.3.0",
            "v0.3.0-rc2",
            "v0.3.0-rc1",
            "v0.2.1",
            "v0.2.0",
            "v0.1.1",
            "v0.1.0",
            "v0.0.5",
            "v0.0.4",
            "v0.0.3",
            "v0.0.2",
            "v0.0.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-48312.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:49.051171418Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/48xxx/CVE-2023-48312.json",
        "https://github.com/projectcapsule/capsule-proxy/security/advisories/GHSA-fpvw-6m5v-hqfp",
        "https://nvd.nist.gov/vuln/detail/CVE-2023-48312",
        "https://github.com/projectcapsule/capsule-proxy/commit/472404f7006a4152e4eec76dee07324dd1e6e823"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-287"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/48xxx/CVE-2023-48312.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2023-48312",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 517364,
  "published_at": "2023-11-24T17:12:39.652+00:00"
}