Out-of-bounds write in PHP - CVE-2019-6977

 

Out-of-bounds write in PHP - CVE-2019-6977

Published: January 10, 2019 / Updated: June 17, 2021


Vulnerability identifier: #VU16916
CSH Severity: High
CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2019-6977
CWE-ID: CWE-787
Exploitation vector: Remote access
Exploit availability: Public exploit is available

Vulnerability details

The vulnerability allows a remote attacker to execute arbitrary on the target system.

The weakness exists due to out-of-bounds write in imagecolormatch. A remote attacker can write up to 1200 bytes over the boundaries of a buffer allocated in the imagecolormatch function, which then calls gdImageColorMatch() and execute arbitrary code with elevated privileges.

Affected software

PHP
Gentoo Linux
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for ARM 64
Slackware Linux
Opensuse
Fedora
Red Hat Software Collections
libgd2 (Ubuntu package)
libgd2 (Debian package)
php7 (Alpine package)
gd (Red Hat package)
gd
Flex System Chassis Management Module (CMM)

How to mitigate CVE-2019-6977

The vulnerability has been fixed in the versions 5.6.40, 7.1.26, 7.2.14, 7.3.1.

PHP - addressed in versions 5.6.40, 7.1.26, 7.2.14, 7.3.1
libgd2 (Ubuntu package) - addressed in versions 2.1.0-3ubuntu0.11, 2.1.1-4ubuntu0.16.04.11, 2.2.5-4ubuntu0.3, 2.2.5-4ubuntu1.1
libgd2 (Debian package) - update to 2.2.4-2+deb9u4
php7 (Alpine package) - update to 7.1.30-r0
Flex System Chassis Management Module (CMM) - update to 2pet18c-2.5.16c
gd (Red Hat package) - update to 2.2.5-7.el8
gd - addressed in versions 2.2.5-8.fc29, 2.2.5-9.fc30, 2.2.5-10.fc31, 2.3.0-1.fc32

Links to Public Exploits and PoC-codes

External References

Related Security Bulletins