CVE Vulnerabilities

CVE-2016-6923

Use After Free

Published: Sep 14, 2016 | Modified: Jan 19, 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
9.3 HIGH
AV:N/AC:M/Au:N/C:C/I:C/A:C
RedHat/V2
6.8 CRITICAL
AV:N/AC:M/Au:N/C:P/I:P/A:P
RedHat/V3
8.8 CRITICAL
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Ubuntu
MEDIUM

Use-after-free vulnerability in Adobe Flash Player before 18.0.0.375 and 19.x through 23.x before 23.0.0.162 on Windows and OS X and before 11.2.202.635 on Linux allows attackers to execute arbitrary code via unspecified vectors, a different vulnerability than CVE-2016-4272, CVE-2016-4279, CVE-2016-6921, CVE-2016-6925, CVE-2016-6926, CVE-2016-6927, CVE-2016-6929, CVE-2016-6930, CVE-2016-6931, and CVE-2016-6932.

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
Flash_player Adobe * 11.2.202.632 (including)
Red Hat Enterprise Linux 5 Supplementary RedHat flash-plugin-0:11.2.202.635-1.el5_11 *
Red Hat Enterprise Linux 6 Supplementary RedHat flash-plugin-0:11.2.202.635-1.el6_8 *
Adobe-flashplugin Ubuntu devel *
Adobe-flashplugin Ubuntu precise *
Adobe-flashplugin Ubuntu trusty *
Adobe-flashplugin Ubuntu upstream *
Adobe-flashplugin Ubuntu xenial *

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