Out-of-bounds read in PHP - CVE-2019-9021
Published: November 1, 2019
Vulnerability identifier: #VU22476
CSH Severity: Medium
CVSS v4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2019-9021
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to gain access to potentially sensitive information.
The vulnerability exists due to a boundary condition within the phar_detect_phar_fname_ext() function in ext/phar/phar.c (PHAR extension) when reading PHAR archives. A remote attacker can create a specially crafted PHAR archive, pass it to the affected application, trigger out-of-bounds read error and read contents of memory on the system.
Affected software
PHP
Red Hat Software Collections
php7 (Alpine package)
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for x86_64
Opensuse
Red Hat Software Collections
php7 (Alpine package)
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for x86_64
Opensuse
How to mitigate CVE-2019-9021
Install updates from vendor's website.
PHP - addressed in versions 5.6.40, 7.1.26, 7.2.14, 7.3.1
php7 (Alpine package) - update to 7.2.17-r0
php7 (Alpine package) - update to 7.2.17-r0