Cyber Resilience

CVE-2021-36393

SQLi in Moodle ≤ 3.9.8

High EPSSSQLi
Published
06 March 2023
Modified
21 November 2024
Patch / advisory
View advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.52 99th percentile
Risk Priority 85 floored blend · peak EPSS

Summary

CVE-2021-36393 is a critical-severity SQL Injection (CWE-89) vulnerability in Moodle Moodle. Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 1% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability Data

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

CWE(s)
CWE-89

Related Threats

Likely ATT&CK TechniquesAI

Techniques this vulnerability likely enables, inferred from its description, weakness type, and attributed-actor tradecraft. Confidence is per-technique.

T1190 Exploit Public-Facing Application Initial Accessconfidence: HIGH
SQL injection in a web application library directly enables exploitation of a public-facing application.
attack.mitre.org →
inferred from description + CWE · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2023-28329Same product: Moodle Moodle
CVE-2024-43436Same product: Moodle Moodle
CVE-2023-35132Same product: Moodle Moodle
CVE-2023-30944Same product: Moodle Moodle
CVE-2024-6216Shared CWE-89
CVE-2023-39526Shared CWE-89
CVE-2023-45376Shared CWE-89
CVE-2024-36683Shared CWE-89
CVE-2023-1566Shared CWE-89
CVE-2023-30192Shared CWE-89

Affected Assets

moodle
moodle
≤ 3.9.8 · 3.10.0 — 3.10.5 · 3.11.0 — 3.11.1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V6.2.5

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

CA-8 Penetration Testing
addresses: CWE-89

Penetration testing uses SQL injection payloads against database interfaces, identifying and supporting fixes for SQL injection weaknesses.

SI-10 Information Input Validation
addresses: CWE-89

Validates query inputs to prevent SQL syntax or command manipulation.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly target injection flaws during coding and review so largely prevent CWE-89 introduction, yet the single broad outcome leaves residual risk from incomplete neutralization techniques or missed edge cases.

PR.AT-02 partial match
prevents

Training raises developer awareness of SQLi risks and can reduce introduction likelihood (partial) but removes none of the actual coding flaw's risk by itself since technical neutralization is still required.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
detects

The same secure-coding and static-analysis activities surface missing neutralization of SQL metacharacters before the system is accepted.

A.5.6 Contact with special interest groups partial match
prevents

Early warnings and shared best-practice information help organizations apply the latest remediation techniques against SQL-injection vulnerabilities.

A.5.7 Threat intelligence partial match
prevents

Threat-intelligence feeds that surface new SQL-injection campaigns enable rapid updates to query-construction defenses and detection signatures before exploitation occurs.

A.8.25 Secure development life cycle partial match
prevents

Secure-coding rules and security testing phases mandate the use of parameterized queries or equivalent escaping, preventing the construction of dynamic SQL statements from untrusted input.

A.8.28 Secure coding partial match
prevents

Language-specific secure coding rules, peer review and SAST together prevent the construction of SQL statements from untrusted data without proper parameterization or escaping.

References