#VU7349 Null pointer dereference in PHP - CVE-2017-9229

Vulnerability identifier: #VU7349

Vulnerability risk: Low

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2017-9229

CWE-ID: CWE-476

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 cause DoS condition.

The weakness exists in the mbstring due to an error in handling of reg->dmin in forward_search_range(). A remote attacker can trigger SIGSEGV in left_adjust_char_head() during regular expression compilation, cause NULL pointer dereference and the application to crash.

Successful exploitation of the vulnerability results in denial of service.

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.