CVE-2021-36934
Act now ● On CISA KEV — actively exploited
Actively exploited — on the CISA KEV list.
CVSS breakdown
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
| Attack Vector | L | Local |
| Attack Complexity | L | Low |
| Privileges Required | L | Low |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | H | High |
| Integrity | H | High |
| Availability | H | High |
Timeline
- 2021-07-22 — Published (NVD)
- 2022-02-10 — Added to CISA KEV (actively exploited)
- 2022-02-24 — CISA patch-by deadline
- 2026-08-10 — Last modified (NVD)
Description
An elevation of privilege vulnerability exists because of overly permissive Access Control Lists (ACLs) on multiple system files, including the Security Accounts Manager (SAM) database. An attacker who successfully exploited this vulnerability could run arbitrary code with SYSTEM privileges. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. An attacker must have the ability to execute code on a victim system to exploit this vulnerability. After installing this security update, you must manually delete all shadow copies of system files, including the SAM database, to fully mitigate this vulnerabilty. Simply installing this security update will not fully mitigate this vulnerability. See KB5005357- Delete Volume Shadow Copies.
Affected
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-36934
- http://packetstormsecurity.com/files/164006/HiveNightmare-AKA-SeriousSAM.html
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-36934
- https://www.kb.cert.org/vuls/id/506989
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-36934