CVE-2021-1879 Apple iOS, iPadOS, and watchOS: web page flaw
In plain words: A web app can be made to act on someone's behalf or reach places it should not. Stolen sessions, actions taken as the victim, or access to internal systems.
Confirmed exploited by CISA on · US federal patch deadline Nov 17, 2021
What to do
- Install Apple's security update for iOS, iPadOS, and watchOS. 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 watchOS WebKit Cross-Site Scripting (XSS) Vulnerability
- Product
- Apple iOS, iPadOS, and watchOS
- CISA description
- Apple iOS, iPadOS, and watchOS WebKit contain an unspecified vulnerability that allows for universal cross-site scripting (XSS) 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
- Web page flaw (CWE-79)
- Confirmed exploited
- Nov 3, 2021
- US federal patch deadline
- Nov 17, 2021
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Answering about CVE-2021-1879 ·
Questions about CVE-2021-1879
Is CVE-2021-1879 being exploited?
Yes. CISA added CVE-2021-1879 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-2021-1879?
Install Apple's security update for iOS, iPadOS, and watchOS. 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-2021-1879?
Only if you use Apple iOS, iPadOS, and watchOS. This one is aimed at devices or apps of the kind people own.