CVE-2021-30813

Local Login Window bypass via Remote Desktop

Published Oct 28, 2021 · Updated Aug 3, 2024

Authentication bypass in Apple macOS before 12.0.1 allows local users to bypass the Login Window through Remote Desktop. Apple identifies a logic issue in the Login Window and says improved checks corrected it, but does not disclose which check mishandled Remote Desktop access. Exploitation requires access to a host Mac and a locked macOS instance, and successful bypass grants access past the login boundary without reported confidentiality or availability impact.

CVSS severity6.5
Medium
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Authentication bypass in Apple macOS before 12.0.1 allows local users to bypass the Login Window through Remote Desktop. Apple identifies a logic issue in the Login Window and says improved checks corrected it, but does not disclose which check mishandled Remote Desktop access. Exploitation requires access to a host Mac and a locked macOS instance, and successful bypass grants access past the login boundary without reported confidentiality or availability impact.

The record

CVE
CVE-2021-30813
Published
Oct 28, 2021
Updated
Aug 3, 2024
Vendor
Apple
Product
macOS
Classifications
T1563
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 28, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <12.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Apple · macOSversion=unspecified <12.0

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N
2.1NIST NVDAV:L/AC:L/Au:N/C:N/I:P/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1563Remote Service Session Hijacking

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo