Red Hat Enterprise Linux 7 update for php

1) Buffer overflow

EUVDB-ID: #VU22304

Risk: High

CVSSv4.0: 9.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Amber]

CVE-ID: CVE-2019-11043

CWE-ID: CWE-119 - Memory corruption

Exploit availability: Yes

Description

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

The vulnerability exists due to a boundary error in env_path_info in PHP-FPM when processing untrusted input passed via URL. A remote attacker can send a specially crafted HTTP request to the affected server, trigger memory corruption and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system but requires that php-fpm is used with nginx and certain nginx configuration was applied:

1. The nginx location directive forwards requests to PHP-FPM
2. The fastcgi_split_path_info directive is present and includes a regular expression beginning with a ‘^’ symbol and ending with a ‘$’ symbol
3. The fastcgi_param directive is used to assign the PATH_INFO variable
4. There are no checks in place to determine whether or not a file exists (e.g., using try_files or an if statemen

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux for x86_64 - Extended Update Support: 7.6

Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions: 7.6

Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions: 7.6

Red Hat Enterprise Linux Server - TUS: 7.6

Red Hat Enterprise Linux for Power, little endian - Extended Update Support: 7.6

Red Hat Enterprise Linux EUS Compute Node: 7.6

Red Hat Enterprise Linux for Power, big endian - Extended Update Support: 7.6

Red Hat Enterprise Linux for IBM z Systems - Extended Update Support: 7.6

Red Hat Enterprise Linux Server - AUS: 7.6

Red Hat Enterprise Linux for IBM System z (Structure A): 7.0

Red Hat Enterprise Linux for Power 9: 7.0

Red Hat Enterprise Linux for ARM 64: 7.0

php (Red Hat package): 5.4.16-23.el7_0 - 5.4.16-43.el7_4

CPE2.3

• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_x86_64_-_extended_update_support:7.6:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:a:red_hat:red_hat_enterprise_linux_server_-_update_services_for_sap_solutions:7.6:*:*:*:*:*:*:*
• cpe:2.3:a:red_hat:red_hat_enterprise_linux_server_for_ibm_power_le_-_update_services_for_sap_solutions:7.6:*:*:*:*:*:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_server_-_tus:7.6:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_power_little_endian_-_extended_update_support:7.6:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_eus_compute_node:7.6:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_power_big_endian_-_extended_update_support:7.6:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_ibm_z_systems_-_extended_update_support:7.6:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_server_-_aus:7.6:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_ibm_system_z_structure_a:7.0:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_power_9:7.0:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_arm_64:7.0:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:a:red_hat:php_redhat_package:5.4.16-23.el7_0:*:*:*:*:red_hat_enterprise_linux:*:*

External links

https://access.redhat.com/errata/RHSA-2020:2835

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.