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CVE-2021-1870: Apple iOS, iPadOS, and macOS WebKit Remote Code Execution Vulnerability

CVE-2021-1870 is rated critical with a CVSS v3.1 base score of 9.8 and affects Apple iOS, iPadOS, and macOS, along with 4 other products in NVD’s configuration data. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available. CISA added it to its Known Exploited Vulnerabilities catalog on 2021-11-03, which means exploitation in the wild has been observed.

Vulnerability 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..

Severity breakdown

CVSS v3.1 9.8: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

  • Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
  • Attack complexity: Low. No special conditions; the attack can be repeated reliably.
  • Privileges required: None. No account or prior access is needed.
  • User interaction: None. No action from any user is needed.
  • Scope: Unchanged. Impact stays within the vulnerable component.
  • Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
  • Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
  • Availability impact: High. Total loss of availability; the component can be shut down.

Affected products

  • Apple Ipados: before 14.4
  • Apple macOS: from 11.0.1 before 11.2
  • Apple Iphone OS: before 14.4
  • Apple Mac OS X: from 10.15 before 10.15.7; 10.15.7; 10.15.7 security_update_2020-001; 10.15.7 supplemental_update
  • Webkitgtk: before 2.30.6
  • Fedoraproject: 32; 33

References