‹ Back to list

CVE-2021-36393

Status: ModifiedCritical (9.8)—PoC
Severity9.8Critical · CVSS 3.1
Exploitation probability52 %higher than 99% of CVEs
Active exploitationNonot in the CISA catalog
Public exploitAvailableProof of concept on GitHub (unverified)

In Moodle, an SQL injection risk was identified in the library fetching a user's recent courses.

CVSS

Base score
9.8
Version
3.1
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days
52 %
Percentile among all scored CVEs
99
Score date
10/21/2026

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).

Public exploits

Exploit code or detection templates are publicly available. This is not the same as confirmed active exploitation (KEV), but it raises the risk: patch with priority.

⚠️ GitHub proofs of concept are not verified: some are fake or contain malware. Never run them outside an isolated lab.

Affected technologies (1)

Moodle — Moodle

CWEs

References

Show 2 references

Raw JSON (NVD)

Show
{
  "id": "CVE-2021-36393",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2021-36393",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2025-03-06T15:45:19.973198Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 9.8,
          "attackVector": "NETWORK",
          "baseSeverity": "CRITICAL",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "patrick@puiterwijk.org",
      "affectedData": [
        {
          "vendor": "n/a",
          "product": "Moodle",
          "versions": [
            {
              "status": "affected",
              "version": "3.11, 3.10 to 3.10.4, 3.9 to 3.9.7 and earlier unsupported versions"
            }
          ]
        }
      ]
    }
  ],
  "published": "2023-03-06T21:15:10.380",
  "references": [
    {
      "url": "https://moodle.org/mod/forum/discuss.php?d=424798",
      "tags": [
        "Patch",
        "Vendor Advisory"
      ],
      "source": "patrick@puiterwijk.org"
    },
    {
      "url": "https://moodle.org/mod/forum/discuss.php?d=424798",
      "tags": [
        "Patch",
        "Vendor Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "patrick@puiterwijk.org",
      "description": [
        {
          "lang": "en",
          "value": "CWE-89"
        }
      ]
    },
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-89"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In Moodle, an SQL injection risk was identified in the library fetching a user's recent courses."
    }
  ],
  "lastModified": "2026-06-17T03:58:47.863",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:moodle:moodle:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "6ED9E7B8-EAD3-4BE3-BC62-E2B9926EE426",
              "versionEndExcluding": "3.9.8"
            },
            {
              "criteria": "cpe:2.3:a:moodle:moodle:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "5F564F50-7DC5-4243-897A-D9334AC7B1BE",
              "versionEndExcluding": "3.10.5",
              "versionStartIncluding": "3.10.0"
            },
            {
              "criteria": "cpe:2.3:a:moodle:moodle:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "F54C5456-58D7-4042-96FA-BD88C9B88EB0",
              "versionEndExcluding": "3.11.1",
              "versionStartIncluding": "3.11.0"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "patrick@puiterwijk.org"
}