Race condition in PHP - CVE-2019-9637

Vulnerability identifier: #VU21220

CSH Severity: Low

CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2019-9637

CWE-ID: CWE-362

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a race condition when renaming files on the system, as the rename() PHP function temporary creates files with weak privileges. A local user can exploit this behavior to gain access to sensitive information.

PHP
Amazon Linux AMI
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for ARM 64
Red Hat Software Collections
php7 (Alpine package)
Flex System Chassis Management Module (CMM)

Install updates from vendor's website.

PHP - addressed in versions 7.1.27, 7.2.16, 7.3.3
php7 (Alpine package) - addressed in versions 7.1.30-r0, 7.2.17-r0
Flex System Chassis Management Module (CMM) - update to 2pet18c-2.5.16c

• https://bugs.php.net/bug.php?id=77630

• Amazon Linux AMI update for php71, php72, php73
• Red Hat update for rh-php72-php
• Red Hat Enterprise Linux 8 update for the php:7.2 module
• Race condition in php7 (Alpine package)
• Multiple vulnerabilities in IBM Flex System Chassis Management Module (CMM)