Security restrictions bypass in PHP

1) Input validation error

EUVDB-ID: #VU49338

Risk: Medium

CVSSv3.1: 4.8 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:P/RL:O/RC:C]

CVE-ID: CVE-2020-7071

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass implemented security restrictions.

The vulnerability exists due to insufficient validation of URL performed via the "FILTER_VALIDATE_URL" setting. A remote attacker can use the "@" characters in the URL to bypass implemented filter and force the application to accept arbitrary URL instead of the defined by the option.

Example:

http://evel.website@trusted.website

Mitigation

Install updates from vendor's website.

Vulnerable software versions

PHP: 7.3 - 8.0.0

CPE2.3

• cpe:2.3:a:php_group:php:7.3.25:*:*:*:*:*:*:
• cpe:2.3:a:php_group:php:7.4.13:*:*:*:*:*:*:
• cpe:2.3:a:php_group:php:8.0.0:*:*:*:*:*:*:

External links

http://www.php.net/ChangeLog-7.php#7.4.14
http://www.php.net/ChangeLog-7.php#7.3.26
http://bugs.php.net/bug.php?id=77423

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.