1. Cleus
  2. Zero-days
  3. CVE-2021-30661
Exploited in the wildWeb browsersCould reach you

CVE-2021-30661 Apple Multiple Products: memory-safety flaw

In plain words: The program mishandles the memory it uses to keep track of data. A specially made input can scramble that memory. Usually lets an attacker crash the program or run their own code with its permissions.

Confirmed exploited by CISA on · US federal patch deadline Nov 17, 2021

What to do

  1. Install Apple's security update for Multiple Products. If no update exists, follow the vendor's workaround or stop using the product until one ships.
  2. Let the browser auto-update and relaunch it when it asks — the fix is not active until you do.
  3. Keep extensions to a minimum and remove ones you do not recognise.
  4. Stop using Internet Explorer and any browser that no longer gets updates.

Who is affected

Could reach you. This one is aimed at devices or apps of the kind people own.

What's at risk: A malicious or hacked website can be enough. Browser bugs are often the first step in a longer attack on the whole computer or phone.

The details

Official name
Apple Multiple Products WebKit Storage Use-After-Free Vulnerability
Product
Apple Multiple Products
CISA description
Apple iOS, iPadOS, macOS, tvOS, watchOS, and Safari WebKit Storage contain a use-after-free vulnerability that leads to code execution when processing maliciously crafted web content. This vulnerability could impact HTML parsers that use WebKit, including but not limited to Apple Safari and non-Apple products which rely on WebKit for HTML processing.
Type of flaw
Memory-safety flaw (CWE-416)
Confirmed exploited
Nov 3, 2021
US federal patch deadline
Nov 17, 2021

Ask Cleus about it

Ask about a vulnerability, an update, a weird message, or the news. Plain-word answers, free, no account.

Answering about CVE-2021-30661 ·

Questions about CVE-2021-30661

Is CVE-2021-30661 being exploited?

Yes. CISA added CVE-2021-30661 to its Known Exploited Vulnerabilities catalog on Nov 3, 2021, which means there is reliable evidence of real-world attacks.

How do I fix CVE-2021-30661?

Install Apple's security update for Multiple Products. If no update exists, follow the vendor's workaround or stop using the product until one ships. Let the browser auto-update and relaunch it when it asks — the fix is not active until you do.

Am I affected by CVE-2021-30661?

Only if you use Apple Multiple Products. This one is aimed at devices or apps of the kind people own.

Other exploited Apple vulnerabilities

Newest in the catalog

Search every known exploited vulnerability →