Out-of-bounds write in macOS - CVE-2021-1881
Published: April 27, 2021 / Updated: May 21, 2021
Vulnerability identifier: #VU52609
CSH Severity: High
CVSS v4: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2021-1881
CWE-ID: CWE-787
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a boundary error when processing font files within the GetFDIndex function in libFontParser. A remote attacker can create a specially crafted OTF font, trick the victim into a document of a web page with the malicious font, trigger out-of-bounds write and execute arbitrary code on the target system.
Affected software
macOS
watchOS
iPadOS
tvOS
Apple iOS
watchOS
iPadOS
tvOS
Apple iOS
How to mitigate CVE-2021-1881
Install updates from vendor's website.
macOS - addressed in versions 10.14.6 18G9028, 10.15.7 19H1030, 11.3 20E232
watchOS - update to 7.4 18T195
iPadOS - update to 14.5 18E199
tvOS - update to 14.5 18L204
Apple iOS - update to 14.5 18E199
watchOS - update to 7.4 18T195
iPadOS - update to 14.5 18E199
tvOS - update to 14.5 18L204
Apple iOS - update to 14.5 18E199