Vulnerability identifier: #VU52790

Vulnerability risk: Medium

CVSSv3.1: 7.7 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-21264

CWE-ID: CWE-94

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
October CMS
Web applications / CMS

Vendor: OctoberCMS

Description

The vulnerability allows a remote user to execute arbitrary PHP code on the target system.

The vulnerability exists due to incomplete patch implementation for previously patched vulnerabilities #VU48707 and #VU48710. A remote authenticated user with the cms.manage_pages, cms.manage_layouts, or cms.manage_partials permissions can  write specific Twig code to escape the Twig sandbox and execute arbitrary PHP.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

October CMS: 1.1.1, 1.0.470 - 1.0.471

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External links
http://github.com/octobercms/october/security/advisories/GHSA-fcr8-6q7r-m4wg/

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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.