#VU9956 Deserialization of untrusted data in PHP - CVE-2017-12933

Vulnerability identifier: #VU9956

Vulnerability risk: Low

CVSSv4.0: 4.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2017-12933

CWE-ID: CWE-502

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 a buffer over-read while unserializing untrusted data in the finish_nested_data function in ext/standard/var_unserializer.re. A remote attacker can perform a denial of service attack.

Mitigation
The vendor has issued the following versions to address this vulnerability: 5.6.31, 7.0.21, 7.1.7.

Vulnerable software versions

PHP: 5.6.0 - 5.6.30, 7.0.0 - 7.0.20, 7.1.0 - 7.1.6

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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=74111

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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.