Vulnerability identifier: #VU18283

Vulnerability risk: Medium

CVSSv3.1: 5.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:P/RL:O/RC:C]

CVE-ID: CVE-2018-17583

CWE-ID: CWE-79

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
WP Fastest Cache
Web applications / Modules and components for CMS

Vendor: Emre Vona

Description

The vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists due to insufficient sanitization of user-supplied data when processing the rules[0][content] parameter in a wpfc_save_exclude_pages action. A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.

Mitigation
Install update from vendor's website.

Vulnerable software versions

WP Fastest Cache: 0.8.8.5

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External links
http://ansawaf.blogspot.com/2019/04/csrf-multiple-stored-xss-in-wp-fastest.html
http://docs.google.com/document/d/17JSC97ecikWalB_ZTScNipFoud2aFXb5mXEZ7g-KIQI/edit?usp=sharing

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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.