cve-2023-54391

{
  "cvss": 9.3,
  "datePublished": "2026-09-01T22:17:10.283",
  "dateUpdated": "2026-09-08T20:18:59.270",
  "description": "Proxmox Virtual Environment (VE) 7.0 through 8.0 contains an authentication bypass vulnerability in libpve-access-control before 8.0.4 that allows unauthenticated attackers to authenticate as any existing enabled user without a configured second factor by supplying an arbitrary tfa-challenge value in the API login endpoint. Attackers can send a POST request to the access ticket API endpoint with any value in the tfa-challenge parameter to completely skip password verification, gaining unauthorized access including to the root@pam account. All affected releases are end of life.",
  "id": "CVE-2023-54391",
  "raw": {
    "affected": [
      {
        "affectedData": [
          {
            "defaultStatus": "unaffected",
            "product": "Proxmox Virtual Environment (VE)",
            "vendor": "Proxmox Server Solutions GmbH",
            "versions": [
              {
                "lessThanOrEqual": "7.4",
                "status": "affected",
                "version": "7.0",
                "versionType": "custom"
              },
              {
                "status": "affected",
                "version": "8.0",
                "versionType": "custom"
              }
            ]
          }
        ],
        "source": "disclosure@vulncheck.com"
      }
    ],
    "cveTags": [
      {
        "sourceIdentifier": "disclosure@vulncheck.com",
        "tags": [
          "unsupported-when-assigned"
        ]
      }
    ],
    "descriptions": [
      {
        "lang": "en",
        "value": "Proxmox Virtual Environment (VE) 7.0 through 8.0 contains an authentication bypass vulnerability in libpve-access-control before 8.0.4 that allows unauthenticated attackers to authenticate as any existing enabled user without a configured second factor by supplying an arbitrary tfa-challenge value in the API login endpoint. Attackers can send a POST request to the access ticket API endpoint with any value in the tfa-challenge parameter to completely skip password verification, gaining unauthorized access including to the root@pam account. All affected releases are end of life."
      }
    ],
    "id": "CVE-2023-54391",
    "lastModified": "2026-09-08T20:18:59.270",
    "metrics": {
      "cvssMetricV31": [
        {
          "cvssData": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "exploitabilityScore": 3.9,
          "impactScore": 5.9,
          "source": "disclosure@vulncheck.com",
          "type": "Secondary"
        }
      ],
      "cvssMetricV40": [
        {
          "cvssData": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "availabilityRequirement": "NOT_DEFINED",
            "baseScore": 9.3,
            "baseSeverity": "CRITICAL",
            "confidentialityRequirement": "NOT_DEFINED",
            "exploitMaturity": "NOT_DEFINED",
            "integrityRequirement": "NOT_DEFINED",
            "modifiedAttackComplexity": "NOT_DEFINED",
            "modifiedAttackRequirements": "NOT_DEFINED",
            "modifiedAttackVector": "NOT_DEFINED",
            "modifiedPrivilegesRequired": "NOT_DEFINED",
            "modifiedSubAvailabilityImpact": "NOT_DEFINED",
            "modifiedSubConfidentialityImpact": "NOT_DEFINED",
            "modifiedSubIntegrityImpact": "NOT_DEFINED",
            "modifiedUserInteraction": "NOT_DEFINED",
            "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
            "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
            "modifiedVulnIntegrityImpact": "NOT_DEFINED",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "source": "disclosure@vulncheck.com",
          "type": "Secondary"
        }
      ],
      "ssvcV203": [
        {
          "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "ssvcData": {
            "id": "CVE-2023-54391",
            "options": [
              {
                "exploitation": "none"
              },
              {
                "automatable": "yes"
              },
              {
                "technicalImpact": "total"
              }
            ],
            "role": "CISA Coordinator",
            "timestamp": "2026-09-02T11:55:35.310993Z",
            "version": "2.0.3"
          }
        }
      ]
    },
    "published": "2026-09-01T22:17:10.283",
    "references": [
      {
        "source": "disclosure@vulncheck.com",
        "url": "https://forum.proxmox.com/threads/proxmox-virtual-environment-security-advisories.149331/page-4#post-867929"
      },
      {
        "source": "disclosure@vulncheck.com",
        "url": "https://git.proxmox.com/?p=pve-access-control.git;a=commit;h=032e7d6d441f89a48cadfd7f47e957c8a561c022"
      },
      {
        "source": "disclosure@vulncheck.com",
        "url": "https://git.proxmox.com/?p=pve-access-control.git;a=commit;h=032e7d6d441f89a48cadfd7f47e957c8a561c022"
      },
      {
        "source": "disclosure@vulncheck.com",
        "url": "https://git.proxmox.com/?p=pve-access-control.git;a=commit;h=032e7d6d441f89a48cadfd7f47e957c8a561c022"
      },
      {
        "source": "disclosure@vulncheck.com",
        "url": "https://git.proxmox.com/?p=pve-access-control.git;a=commit;h=032e7d6d441f89a48cadfd7f47e957c8a561c022"
      },
      {
        "source": "disclosure@vulncheck.com",
        "url": "https://git.proxmox.com/?p=pve-access-control.git;a=commit;h=0f3d14d6be4d9f23e511701696a529ef3b7ffd61"
      },
      {
        "source": "disclosure@vulncheck.com",
        "url": "https://www.vulncheck.com/advisories/proxmox-ve-authentication-bypass-via-tfa-challenge-parameter"
      }
    ],
    "sourceIdentifier": "disclosure@vulncheck.com",
    "vulnStatus": "Deferred",
    "weaknesses": [
      {
        "description": [
          {
            "lang": "en",
            "value": "CWE-304"
          }
        ],
        "source": "disclosure@vulncheck.com",
        "type": "Secondary"
      }
    ]
  },
  "severity": "CRITICAL",
  "source": "nvd",
  "title": "Proxmox Virtual Environment (VE) 7.0 through 8.0 contains an authentication bypass vulnerability in libpve-access-con..."
}