CVE

CVE-2021-21264

Date: (C)2021-05-04   (M)2023-12-22

October is a free, open-source, self-hosted CMS platform based on the Laravel PHP Framework. A bypass of CVE-2020-26231 (fixed in 1.0.470/471 and 1.1.1) was discovered that has the same impact as CVE-2020-26231 & CVE-2020-15247. An authenticated backend user with the `cms.manage_pages`, `cms.manage_layouts`, or `cms.manage_partials` permissions who would **normally** not be permitted to provide PHP code to be executed by the CMS due to `cms.enableSafeMode` being enabled is able to write specific Twig code to escape the Twig sandbox and execute arbitrary PHP. This is not a problem for anyone that trusts their users with those permissions to normally write & manage PHP within the CMS by not having `cms.enableSafeMode` enabled, but would be a problem for anyone relying on `cms.enableSafeMode` to ensure that users with those permissions in production do not have access to write & execute arbitrary PHP. Issue has been patched in Build 472 (v1.0.472) and v1.1.2. As a workaround, apply https://github.com/octobercms/october/commit/f63519ff1e8d375df30deba63156a2fc97aa9ee7 to your installation manually if unable to upgrade to Build 472 or v1.1.2.

CVSS Score and Metrics +CVSS Score and Metrics -

CVSS V3 Severity:		CVSS V2 Severity:
CVSS Score : 5.2		CVSS Score : 4.4
Exploit Score: 1.1		Exploit Score: 3.4
Impact Score: 3.7		Impact Score: 6.4
CVSS V3 Metrics:		CVSS V2 Metrics:
Attack Vector: LOCAL		Access Vector: LOCAL
Attack Complexity: LOW		Access Complexity: MEDIUM
Privileges Required: HIGH		Authentication: NONE
User Interaction: REQUIRED		Confidentiality: PARTIAL
Scope: CHANGED		Integrity: PARTIAL
Confidentiality: LOW		Availability: PARTIAL
Integrity: LOW
Availability: LOW

Reference:

https://github.com/octobercms/october/security/advisories/GHSA-fcr8-6q7r-m4wg