Vulnerability identifier: #VU49230

Vulnerability risk: Low

CVSSv3.1: 5.8 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N/E:P/RL:O/RC:C]

CVE-ID: CVE-2020-5809

CWE-ID: CWE-79

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Umbraco CMS
Web applications / CMS

Vendor: Umbraco

Description

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

The vulnerability exists due to insufficient sanitization of user-supplied data within iframes in rich-text content editor. A remote authenticated attacker can permanently inject 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

Umbraco CMS: 8.0.0 - 8.9.1

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External links
http://www.tenable.com/security/research/tra-2020-59

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user 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.