Dangerous file upload in Backdrop CMS

1) Dangerous file upload

EUVDB-ID: #VU18065

Risk: Medium

CVSSv3.1: 4.7 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-6341

CWE-ID: CWE-434 - Unrestricted Upload of File with Dangerous Type

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 within the File module/subsystem in file.inc component. A remote authenticated attacker can upload a file with JavaScript code inside and execute it 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

Update Backdrop Core to version 1.12.5 or 1.11.8.

Vulnerable software versions

Backdrop CMS: 1.11.0 - 1.12.4

External links

http://backdropcms.org/security/backdrop-sa-core-2019-008

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.