CVE-2021-1871 Apple iOS, iPadOS, and macOS: command or code injection
In plain words: The program treats text it receives as instructions instead of plain data. The attacker can run commands on the machine — often the whole device is taken over.
Confirmed exploited by CISA on · US federal patch deadline Nov 17, 2021
What to do
- Install Apple's security update for iOS, iPadOS, and macOS. 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.
- Keep extensions to a minimum and remove ones you do not recognise.
- 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 iOS, iPadOS, and macOS WebKit Remote Code Execution Vulnerability
- Product
- Apple iOS, iPadOS, and macOS
- CISA description
- Apple iOS, iPadOS, and macOS WebKit contain an unspecified logic vulnerability that allows a remote attacker to execute code. 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
- Command or code injection (CWE-1173)
- Confirmed exploited
- Nov 3, 2021
- US federal patch deadline
- Nov 17, 2021
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Answering about CVE-2021-1871 ·
Questions about CVE-2021-1871
Is CVE-2021-1871 being exploited?
Yes. CISA added CVE-2021-1871 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-2021-1871?
Install Apple's security update for iOS, iPadOS, and macOS. 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-2021-1871?
Only if you use Apple iOS, iPadOS, and macOS. This one is aimed at devices or apps of the kind people own.