Vulnerability identifier: #VU28769

Vulnerability risk: Low

CVSSv3.1: 5 [CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N/E:P/RL:O/RC:C]

CVE-ID: CVE-2020-11083

CWE-ID: CWE-79

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
October CMS
Web applications / CMS

Vendor: OctoberCMS

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 in the FormWidget. A remote authenticated user with access to the FormWidget (backend.allow_unsafe_markdown permission) can 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 updates from vendor's website.

Vulnerable software versions

October CMS: 1.0.319 - 1.0.465

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External links
http://github.com/octobercms/october/security/advisories/GHSA-w4pj-7p68-3vgv

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Q & A

Can this vulnerability be exploited remotely?

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