CVE DATABASE / CVE-2021-1879
CVE-2021-1879
Apple iOS, iPadOS, and watchOS WebKit Cross-Site Scripting (XSS) Vulnerability
Confirmed exploited in the wild. Added 2021-11-03.
Federal remediation due 2021-11-17.
Required action: Apply updates per vendor instructions.
Summary
This issue was addressed by improved management of object lifetimes. This issue is fixed in iOS 12.5.2, iOS 14.4.2 and iPadOS 14.4.2, watchOS 7.3.3. Processing maliciously crafted web content may lead to universal cross site scripting. Apple is aware of a report that this issue may have been actively exploited..
CVSS 3.1 breakdown
| Base score | 6.1 (MEDIUM) |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
| Attack vector | NETWORK |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | REQUIRED |
| Scope | CHANGED |
| Confidentiality | LOW |
| Integrity | LOW |
| Availability | NONE |
Weakness type (CWE)
Affected products
Use our free CVE Lookup tool for the latest NVD record, or browse the full CISA KEV catalog.
References
- https://support.apple.com/en-us/HT212256
- https://support.apple.com/en-us/HT212257
- https://support.apple.com/en-us/HT212258
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-1879
Data: NIST NVD + CISA KEV. NVD last modified 2025-10-23. Always verify against the vendor advisory before acting.