Used in attacks· fix by 2021-11-17Not scored yet
Apple iOS, iPadOS, and macOS
CVE-2021-30858
Apple iOS, iPadOS, and macOS WebKit 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.
What this means for your business
- It affects Apple iOS, iPadOS, and macOS. It matters if your company, or a supplier that handles your data, runs it.
- Attackers are already using it. CISA added it to its list of flaws used in real attacks on 3 November 2021.
- FIRST's prediction model gives it a 13% chance of attack attempts being seen in the next 30 days, ranking above 96% of all known flaws.
What to do
- 1Check whether your company or your suppliers run Apple iOS, iPadOS, and macOS.
- 2If you do, follow CISA's required action below. No patch reference has been published yet.
- 3Treat it as urgent. US federal agencies must fix it by 17 November 2021. That deadline does not apply to private companies, but it shows how seriously CISA takes it.
- 4Because attackers have used it, check the affected systems for signs of a break-in, not only for the update.
Not sure if your company is exposed?
Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.
Required action
Apply updates per vendor instructions.
CISA’s wording, unedited.
Scoring
- CVSS
- Not yet scored
Dates
- Published
- 2021-11-03
- Added to KEV
- 2021-11-03
- Remediation due
- 2021-11-17
- Sources
- CISA KEV