CVE Vulnerabilities

CVE-2021-1788

Use After Free

Published: Apr 02, 2021 | Modified: Nov 07, 2023
CVSS 3.x
8.8
HIGH
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS 2.x
6.8 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P
RedHat/V2
RedHat/V3
8.8 MODERATE
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Ubuntu
MEDIUM

A use after free issue was addressed with improved memory management. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, tvOS 14.4, watchOS 7.3, iOS 14.4 and iPadOS 14.4, Safari 14.0.3. Processing maliciously crafted web content may lead to arbitrary code execution.

Weakness

Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code.

Affected Software

Name Vendor Start Version End Version
Ipados Apple * 14.4 (excluding)
Iphone_os Apple * 14.4 (excluding)
Mac_os_x Apple 10.14 (including) 10.14.6 (excluding)
Mac_os_x Apple 10.15 (including) 10.15.7 (excluding)
Mac_os_x Apple 10.14.6 (including) 10.14.6 (including)
Mac_os_x Apple 10.14.6-security_update_2019-004 (including) 10.14.6-security_update_2019-004 (including)
Mac_os_x Apple 10.14.6-security_update_2019-005 (including) 10.14.6-security_update_2019-005 (including)
Mac_os_x Apple 10.14.6-security_update_2019-006 (including) 10.14.6-security_update_2019-006 (including)
Mac_os_x Apple 10.14.6-security_update_2019-007 (including) 10.14.6-security_update_2019-007 (including)
Mac_os_x Apple 10.14.6-security_update_2020-001 (including) 10.14.6-security_update_2020-001 (including)
Mac_os_x Apple 10.14.6-security_update_2020-002 (including) 10.14.6-security_update_2020-002 (including)
Mac_os_x Apple 10.14.6-security_update_2020-003 (including) 10.14.6-security_update_2020-003 (including)
Mac_os_x Apple 10.14.6-security_update_2020-004 (including) 10.14.6-security_update_2020-004 (including)
Mac_os_x Apple 10.14.6-security_update_2020-005 (including) 10.14.6-security_update_2020-005 (including)
Mac_os_x Apple 10.14.6-security_update_2020-006 (including) 10.14.6-security_update_2020-006 (including)
Mac_os_x Apple 10.14.6-security_update_2020-007 (including) 10.14.6-security_update_2020-007 (including)
Mac_os_x Apple 10.14.6-supplemental_update (including) 10.14.6-supplemental_update (including)
Mac_os_x Apple 10.14.6-supplemental_update_2 (including) 10.14.6-supplemental_update_2 (including)
Mac_os_x Apple 10.15.7 (including) 10.15.7 (including)
Mac_os_x Apple 10.15.7-supplemental_update (including) 10.15.7-supplemental_update (including)
Macos Apple 11.0 (including) 11.2 (excluding)
Safari Apple * 14.0.3 (excluding)
Tvos Apple * 14.4 (excluding)
Watchos Apple * 7.3 (excluding)
Red Hat Enterprise Linux 8 RedHat webkit2gtk3-0:2.32.3-2.el8 *
Qtwebkit-opensource-src Ubuntu bionic *
Qtwebkit-opensource-src Ubuntu devel *
Qtwebkit-opensource-src Ubuntu esm-apps/bionic *
Qtwebkit-opensource-src Ubuntu esm-apps/focal *
Qtwebkit-opensource-src Ubuntu esm-apps/jammy *
Qtwebkit-opensource-src Ubuntu esm-apps/noble *
Qtwebkit-opensource-src Ubuntu esm-infra/xenial *
Qtwebkit-opensource-src Ubuntu focal *
Qtwebkit-opensource-src Ubuntu groovy *
Qtwebkit-opensource-src Ubuntu hirsute *
Qtwebkit-opensource-src Ubuntu impish *
Qtwebkit-opensource-src Ubuntu jammy *
Qtwebkit-opensource-src Ubuntu kinetic *
Qtwebkit-opensource-src Ubuntu lunar *
Qtwebkit-opensource-src Ubuntu mantic *
Qtwebkit-opensource-src Ubuntu noble *
Qtwebkit-opensource-src Ubuntu trusty *
Qtwebkit-opensource-src Ubuntu upstream *
Qtwebkit-opensource-src Ubuntu xenial *
Qtwebkit-source Ubuntu bionic *
Qtwebkit-source Ubuntu esm-apps/bionic *
Qtwebkit-source Ubuntu esm-apps/xenial *
Qtwebkit-source Ubuntu trusty *
Qtwebkit-source Ubuntu xenial *
Webkit2gtk Ubuntu bionic *
Webkit2gtk Ubuntu devel *
Webkit2gtk Ubuntu esm-infra/xenial *
Webkit2gtk Ubuntu focal *
Webkit2gtk Ubuntu groovy *
Webkit2gtk Ubuntu hirsute *
Webkit2gtk Ubuntu impish *
Webkit2gtk Ubuntu jammy *
Webkit2gtk Ubuntu kinetic *
Webkit2gtk Ubuntu lunar *
Webkit2gtk Ubuntu mantic *
Webkit2gtk Ubuntu noble *
Webkit2gtk Ubuntu upstream *
Webkit2gtk Ubuntu xenial *
Webkitgtk Ubuntu bionic *
Webkitgtk Ubuntu esm-apps/bionic *
Webkitgtk Ubuntu esm-apps/xenial *
Webkitgtk Ubuntu trusty *
Webkitgtk Ubuntu xenial *
Wpewebkit Ubuntu esm-apps/focal *
Wpewebkit Ubuntu esm-apps/jammy *
Wpewebkit Ubuntu focal *
Wpewebkit Ubuntu groovy *
Wpewebkit Ubuntu hirsute *
Wpewebkit Ubuntu impish *
Wpewebkit Ubuntu jammy *
Wpewebkit Ubuntu trusty *
Wpewebkit Ubuntu upstream *

Extended Description

The use of previously-freed memory can have any number of adverse consequences, ranging from the corruption of valid data to the execution of arbitrary code, depending on the instantiation and timing of the flaw. The simplest way data corruption may occur involves the system’s reuse of the freed memory. Use-after-free errors have two common and sometimes overlapping causes:

In this scenario, the memory in question is allocated to another pointer validly at some point after it has been freed. The original pointer to the freed memory is used again and points to somewhere within the new allocation. As the data is changed, it corrupts the validly used memory; this induces undefined behavior in the process. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap data. If one of these function pointers is overwritten with an address to valid shellcode, execution of arbitrary code can be achieved.

Potential Mitigations

References