#VU7348 Heap-out-of-bounds write in PHP - CVE-2017-9228

Vulnerability identifier: #VU7348

Vulnerability risk: High

CVSSv4.0: 8.1 [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/E:U/U:Amber]

CVE-ID: CVE-2017-9228

CWE-ID: CWE-787

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 execute arbitrary code.

The weakness exists in the mbstring due to heap out-of-bounds write in bitset_set_range() during regular expression compilation due to incorrect state transition in parse_char_class(). A remote attacker can trigger out-of-bounds write memory corruption and execute arbitrary code with web server privileges.

Successful exploitation of the vulnerability may result in system compromise.

Mitigation
Update to version 7.0.21.

Vulnerable software versions

PHP: 7.0.0 - 7.0.20

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External links
https://php.net/ChangeLog-7.php#7.0.21

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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.