CVEs / CVE-2021-1871
CVE-2021-1871: Apple iOS, iPadOS, and macOS WebKit Remote Code Execution Vulnerability
- Known exploited in the CISA KEV catalog since 3 Nov 2021
- critical 9.8 CVSS 3.1 (NVD)
- EPSS 7% chance of exploitation in the next 30 days, higher than 94% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
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.
Description
A logic issue was addressed with improved restrictions. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, iOS 14.4 and iPadOS 14.4. A remote attacker may be able to cause arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited..
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| Apple iOS and iPadOS | from unspecified, before 14.4 | 14.4 |
| Apple macOS | from unspecified, before 11.2 | 11.2 |
Exploitation
| In CISA KEV since | 3 Nov 2021 |
|---|---|
| Due date for US federal agencies | 17 Nov 2021 |
| Used in ransomware campaigns | Unknown |
| Required action | Apply updates per vendor instructions. |
Severity
| CVSS 3.1 | 9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HScored by NVD |
|---|
References
- CVE-2021-1871 on NVD
- CVE-2021-1871 in the CISA KEV catalog
- CVE-2021-1871 on OSV
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L3L6ZZOU5JS7E3RFYGLP7UFLXCG7TNLU/ Broken Link, Mailing List
- https://support.apple.com/en-us/HT212146 Release Notes, Vendor Advisory
- https://support.apple.com/en-us/HT212147 Release Notes, Vendor Advisory
- https://www.debian.org/security/2021/dsa-4923 Mailing List, Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-1871 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.