Exploited vulnerability · CISA KEV

Is CVE-2021-1789 exploited? Yes: in CISA KEV since 4 May 2022

Gociux · Apple Multiple Products · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2021-1789, Apple Multiple Products Type Confusion Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 4 May 2022, 397 days after it was published. It affects Apple Multiple Products. If you run it, CISA's required action is: Apply updates per vendor instructions.

exploitedYesCISA KEV · 4 May 2022

ransomwareNot knownno confirmed use

EPSStop 5%very likely to be exploited

severity8.8CVSS 3.1 · high

US federal due25 May 2022BOD 22-01 deadline

What it is

A type confusion issue affecting multiple Apple products allows processing of maliciously crafted web content, leading to arbitrary code execution.

Vendor	Apple (96 exploited CVEs in KEV)
Product	Multiple Products
Vulnerability	Apple Multiple Products Type Confusion Vulnerability
Weakness	CWE-843
Published	2 Apr 2021
Added to KEV	4 May 2022
Reported by (CNA)	apple

What to do

Check whether you run it. Look for Multiple Products in your asset inventory, including appliances and cloud images. Stack check lists every exploited Apple CVE at once.
Apply the fix. Apply updates per vendor instructions.
If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 2 Apr 2021.
Get told next time. Email alerts when CISA adds a CVE for Apple.

Other exploited CVEs in Multiple Products

CVE-2024-27834: Apple Multiple Products Improper Authentication Vulnerability (4 Nov 2026)
CVE-2026-86950: Apple Multiple Products Out-of-Bounds Write Vulnerability (29 Sep 2026)
CVE-2025-43510: Apple Multiple Products Improper Locking Vulnerability (20 Mar 2026)
CVE-2025-43520: Apple Multiple Products Classic Buffer Overflow Vulnerability (20 Mar 2026)
CVE-2025-31277: Apple Multiple Products Buffer Overflow Vulnerability (20 Mar 2026)
CVE-2023-43000: Apple Multiple products Use-After-Free Vulnerability (5 Mar 2026)

References

nvd.nist.gov/vuln/detail/CVE-2021-1789

Questions

Is CVE-2021-1789 being exploited?

Yes. CISA added CVE-2021-1789 to the Known Exploited Vulnerabilities catalog on 4 May 2022, which means there is reliable evidence of exploitation in the wild.

Is CVE-2021-1789 used in ransomware attacks?

CISA does not list known ransomware use for it. That can change, and exploitation alone is reason to fix it first.

How do I fix CVE-2021-1789?

Apply updates per vendor instructions. Check Apple's advisory for the fixed versions, and if you can't patch quickly, restrict access to the affected Multiple Products and watch it for signs of compromise.

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in May 2022 · Apple scorecard · act-now radar.

Running Apple in a regulated environment?

We check exposure across your estate, patch or mitigate with your team, and set up detection for what attackers do after exploiting it.

Get in touch →