#VU9960 Improper input validation in PHP - CVE-2017-11142

Vulnerability identifier: #VU9960

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2017-11142

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
PHP
Universal components / Libraries / Scripting languages

Vendor: PHP Group

Description
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to improper check for variable length in main/php_variables.c. A remote attacker can cause a CPU consumption denial of service attack by injecting long form variables.

Mitigation
Update to version 5.6.31, 7.0.17 or 7.1.3.

Vulnerable software versions

PHP: 5.6.0 - 5.6.30, 7.0.0 - 7.0.16, 7.1.0 - 7.1.2

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External links
https://php.net/ChangeLog-5.php
https://php.net/ChangeLog-7.php
https://bugs.php.net/bug.php?id=73807
https://github.com/php/php-src/commit/0f8cf3b8497dc45c010c44ed9e96518e11e19fc3
https://github.com/php/php-src/commit/a15bffd105ac28fd0dd9b596632dbf035238fda3
https://openwall.com/lists/oss-security/2017/07/10/6

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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?

No. We are not aware of malware exploiting this vulnerability.