Vulnerability identifier: #VU16320

Vulnerability risk: Low

CVSSv3.1: 6.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C]

CVE-ID: N/A

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 cause DoS condition on the target system.

The weakness exists due to an error if response headers have been already sent or when calling session_id($id) before session_start(). A remote attacker can send response headers and cause the service to crash.

Mitigation
Update to version 7.3.0.

Vulnerable software versions

PHP: 7.1.0 - 7.1.25

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External links
http://bugs.php.net/bug.php?id=74941

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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. However, proof of concept for this vulnerability is available.