Cyber Resilience

CVE-2025-3645

Access Control in Moodle ≤ 4.1.18

Published
25 April 2025
Modified
17 June 2026
Patch / advisory
CVSS Score v3.1 4.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
EPSS Score 0.0034 27th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2025-3645 is a medium-severity Incorrect Authorization (CWE-863) vulnerability in Moodle Moodle. Its CVSS base score is 4.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Account Discovery (T1087); ranked at the 27th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and AC-6 (Least Privilege) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A flaw was found in Moodle. Insufficient capability checks in a messaging web service allowed users to view other users' names and online statuses.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1087 Account Discovery Discovery
Adversaries may attempt to get a listing of valid accounts, usernames, or email addresses on a system or within a compromised environment.
Why these techniques?

The vulnerability in Moodle's messaging web service allows unauthorized users to view other users' names and online statuses, directly facilitating Account Discovery (T1087).

CVEs Like This One

CVE-2025-3647Same product: Moodle Moodle
CVE-2025-26526Same product: Moodle Moodle
CVE-2024-43433Same product: Moodle Moodle
CVE-2025-26531Same product: Moodle Moodle
CVE-2025-62394Same product: Moodle Moodle
CVE-2025-3640Same product: Moodle Moodle
CVE-2025-67856Same product: Moodle Moodle
CVE-2025-26532Same product: Moodle Moodle
CVE-2025-3628Same product: Moodle Moodle
CVE-2025-3644Same product: Moodle Moodle

Affected Assets

moodle
moodle
≤ 4.1.18 · 4.3.0 — 4.3.12 · 4.4.0 — 4.4.8

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • AC-3 Access Enforcement
  • AC-6 Least Privilege
  • AC-4 Information Flow Enforcement
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly requires the messaging web service to enforce capability-based authorization decisions before disclosing user names or online status.

prevent

Ensures users receive only the minimum capabilities needed, eliminating the excessive privileges that allowed unauthorized viewing of other users' presence data.

prevent

Enforces information-flow rules on the web service so that presence and identity attributes cannot flow to unauthorized recipients.

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.AA-05 mostly match
prevents

Defining, enforcing, and reviewing access authorizations and least privilege directly prevents incorrect authorization checks.

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.

prevents

Requiring consistency between access rights and classification plus formal approval steps ensures that the authorization logic correctly distinguishes between entities that should and should not be granted access.

prevents

Enforcing policy-driven approval and role-change reviews stops incorrect or stale authorization decisions from remaining in effect after job changes or terminations.

prevents

By tying access rights to identity, device, location and classification, the control reduces the likelihood that an authorization decision will be based on an incorrect or bypassed policy.

References