CVE-2021-1771

LOWNVD 3.33.3

3.3

This issue was addressed with improved checks. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave. A user that is removed from an iMessage group could rejoin the group.

CVSS v3: 3.3
EG Score: 3.3(low)
EPSS: 47.1%
KEV: Not listed

Published

April 2, 2021

Last Modified

November 21, 2024

References (2)

product-security@applehttps://support.apple.com/en-us/HT212147
af854a3a-2127-422b-91ae-364da2661108https://support.apple.com/en-us/HT212147

Data Freshness Timeline

(refreshed 13× in last 7d / 20× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

2026-06-08 14:15 UTCEPSS rescore
2026-06-08 14:15 UTCEPSS rescore
2026-06-07 15:23 UTCEPSS rescore
2026-06-07 15:23 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-05 22:45 UTCEPSS rescore
2026-06-05 22:45 UTCEPSS rescore
2026-06-05 06:09 UTCEPSS rescore
2026-06-05 06:09 UTCEPSS rescore
2026-06-05 06:08 UTCEPSS rescore
2026-06-04 13:10 UTCEPSS rescore
2026-06-02 20:11 UTCEPSS rescore
2026-06-02 20:11 UTCEPSS rescore
2026-06-01 13:50 UTCEPSS rescore
2026-06-01 13:50 UTCEPSS rescore
2026-05-31 22:29 UTCEPSS rescore
2026-05-31 22:29 UTCEPSS rescore
2026-05-31 00:15 UTCEPSS rescore

Frequently asked(5)

What is CVE-2021-1771?

CVE-2021-1771 is a low vulnerability published on April 2, 2021. This issue was addressed with improved checks. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave. A user that is removed from an iMessage group could rejoin the group.

When was CVE-2021-1771 disclosed?

CVE-2021-1771 was first published in the National Vulnerability Database on April 2, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-1771 actively exploited?

CVE-2021-1771 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 47.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-1771?

CVE-2021-1771 has a CVSS v3 base score of 3.3 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..

How do I remediate CVE-2021-1771?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-1771, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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CVE-2021-1771

📅 Published

🔄 Last Modified

🔗 References (2)