#VU4862 Insufficient randomization in WordPress - CVE-2017-5493

Vulnerability identifier: #VU4862

Vulnerability risk: Medium

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

CVE-ID: CVE-2017-5493

CWE-ID: CWE-330

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
WordPress
Web applications / CMS

Vendor: WordPress.ORG

Description

The vulnerability allows a remote attacker to bypass certain security restriction.

The vulnerability exists due to an error when choosing random numbers for keys within wp-includes/ms-functions.php script in the Multisite WordPress API. A remote attacker can create a specially crafted site signup or user signup request and bypass intended access restriction.

Successful exploitation of the vulnerability may allow an attacker to gain access to otherwise restricted functionality.

Mitigation
Update to version 4.7.1.

Vulnerable software versions

WordPress: 4.7

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External links
https://wordpress.org/news/2017/01/wordpress-4-7-1-security-and-maintenance-release/

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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.