Stored cross-site scripting in BlackCat CMS

1) Stored cross-site scripting

EUVDB-ID: #VU50772

Risk: Low

CVSSv3.1: 5.9 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N/E:U/RL:U/RC:C]

CVE-ID: CVE-2021-27237

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Exploit availability: No

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 Display Name field in "backend/preferences/ajax_save.php". 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

Cybersecurity Help is currently unaware of any official solution to address this vulnerability..

Vulnerable software versions

BlackCat: 1.3.6

External links

http://github.com/BlackCatDevelopment/BlackCatCMS/commits/release-1.4/upload/backend/preferences/ajax_save.php
http://github.com/BlackCatDevelopment/BlackCatCMS/compare/1.3.6...1.4Beta
http://www.exploit-db.com/exploits/49565

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.