CVE-2021-36403
Published: 06 March 2023
Summary
CVE-2021-36403 is a medium-severity Hidden Functionality (CWE-912) vulnerability in Moodle Moodle. Its CVSS base score is 5.3 (Medium).
Operationally, ranked in the top 46.6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-1048
Vulnerability details
In Moodle, in some circumstances, email notifications of messages could have the link back to the original message hidden by HTML, which may pose a phishing risk.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
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.
Documenting every system component at the required granularity and reviewing the inventory detects or prevents hidden functionality from remaining undetected.
Recovery eliminates hidden functionality or backdoors introduced during compromise.
Policy requires supplier transparency and testing to detect hidden functionality or backdoors inserted in the supply chain.
Screening high-risk technical positions lowers the probability that hidden functionality or backdoors will be added by authorized personnel.
Hunting identifies hidden functionality used for persistence or evasion after initial compromise.
TSCM surveys discover and eliminate hidden surveillance functionality that would otherwise remain undetected in the environment.
Change control, approval gates, and flaw tracking force hidden functionality to be either documented or discovered and removed.
Vetting and integrity controls during acquisition reduce the likelihood of hidden backdoors or malicious functionality introduced by suppliers.