‹ Back to list

CVE-2021-36383

Status: ModifiedMedium (4.3)—
Severity4.3Medium · CVSS 3.1
Exploitation probability0.71 %higher than 53% of CVEs
Active exploitationNonot in the CISA catalog
Public exploitNot knownno public code found

Xen Orchestra (with xo-web through 5.80.0 and xo-server through 5.84.0) mishandles authorization, as demonstrated by modified WebSocket resourceSet.getAll data is which the attacker changes the permission field from none to admin. The attacker gains access to data sets such as VMs, Backups, Audit, Users, and Groups.

CVSS

Base score
4.3
Version
3.1
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days
0.71 %
Percentile among all scored CVEs
53
Score date
10/20/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (2)

Xen-orchestra — Xo-serverXen-orchestra — Xo-web

CWEs

References

Show 2 references

Raw JSON (NVD)

Show
{
  "id": "CVE-2021-36383",
  "cveTags": [],
  "metrics": {
    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 4,
          "accessVector": "NETWORK",
          "vectorString": "AV:N/AC:L/Au:S/C:P/I:N/A:N",
          "authentication": "SINGLE",
          "integrityImpact": "NONE",
          "accessComplexity": "LOW",
          "availabilityImpact": "NONE",
          "confidentialityImpact": "PARTIAL"
        },
        "acInsufInfo": false,
        "impactScore": 2.9,
        "baseSeverity": "MEDIUM",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 8,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 4.3,
          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "LOW"
        },
        "impactScore": 1.4,
        "exploitabilityScore": 2.8
      }
    ]
  },
  "affected": [
    {
      "source": "cve@mitre.org",
      "affectedData": [
        {
          "vendor": "n/a",
          "product": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ]
    }
  ],
  "published": "2021-07-12T14:15:11.770",
  "references": [
    {
      "url": "https://github.com/vatesfr/xen-orchestra/issues/5712",
      "tags": [
        "Exploit",
        "Issue Tracking",
        "Third Party Advisory"
      ],
      "source": "cve@mitre.org"
    },
    {
      "url": "https://github.com/vatesfr/xen-orchestra/issues/5712",
      "tags": [
        "Exploit",
        "Issue Tracking",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-Other"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Xen Orchestra (with xo-web through 5.80.0 and xo-server through 5.84.0) mishandles authorization, as demonstrated by modified WebSocket resourceSet.getAll data is which the attacker changes the permission field from none to admin. The attacker gains access to data sets such as VMs, Backups, Audit, Users, and Groups."
    },
    {
      "lang": "es",
      "value": "Xen Orchestra (con xo-web versiones hasta 5.80.0 y xo-server versiones hasta 5.84.0) maneja inapropiadamente la autorización, como es demostrado por los datos modificados de WebSocket resourceSet.getAll en los que el atacante cambia el campo permission de none a admin. El atacante obtiene acceso a conjuntos de datos como VMs, Copias de Seguridad, Auditoría, Usuarios y Grupos"
    }
  ],
  "lastModified": "2026-06-17T03:58:47.003",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:xen-orchestra:xo-server:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "D28E9332-7ACF-4554-81C0-ECA4BDE1DB0F",
              "versionEndIncluding": "5.84.0"
            },
            {
              "criteria": "cpe:2.3:a:xen-orchestra:xo-web:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "9AFB1AD0-37E5-401A-8EE4-B61CD438C4C8",
              "versionEndIncluding": "5.80.0"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "cve@mitre.org"
}