// For flags

CVE-2021-21264

Bypass of fix for CVE-2020-26231, Twig sandbox escape

Severity Score

5.2
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

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.

October es una plataforma CMS gratuita, de código abierto y autohosteada basada en Laravel PHP Framework. Se detectó una omisión de CVE-2020-26231 (corregido en las versiones 1.0.470/471 y 1.1.1) que tiene el mismo impacto que CVE-2020-26231 y CVE-2020-15247. Un usuario de back-end autenticado con los permisos "cms.manage_pages", "cms.manage_layouts" o "cms.manage_partials" que **normalmente** no podría proporcionar código PHP para ser ejecutado por el CMS debido a "cms.enableSafeMode" que está habilitado es capaz de escribir código Twig específico para escapar del sandbox Twig y ejecutar PHP arbitrario. Esto no es un problema para cualquiera que confíe a sus usuarios con esos permisos para escribir y administrar PHP normalmente dentro del CMS al no tener habilitado "cms.enableSafeMode", pero sería un problema para cualquiera que confíe en "cms.enableSafeMode" para asegurarse de que los usuarios con esos permisos en producción no tienen acceso para escribir y ejecutar PHP arbitrario. El problema se corrigió en la compilación 472 (v1.0.472) y v1.1.2. Como solución alternativa, aplique https://github.com/octobercms/october/commit/f63519ff1e8d375df30deba63156a2fc97aa9ee7 a su instalación manualmente si no puede actualizar a la compilación 472 o v1.1.2.

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
High
User Interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
Low
Attack Vector
Local
Attack Complexity
Medium
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2020-12-22 CVE Reserved
  • 2021-05-03 CVE Published
  • 2023-03-08 EPSS Updated
  • 2024-08-03 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-862: Missing Authorization
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Octobercms
Search vendor "Octobercms"
 October
Search vendor "Octobercms" for product "October"
 <= 1.0.471
Search vendor "Octobercms" for product "October" and version " <= 1.0.471"
-
Affected
Octobercms
Search vendor "Octobercms"
 October
Search vendor "Octobercms" for product "October"
 >= 1.1.0 <= 1.1.1
Search vendor "Octobercms" for product "October" and version " >= 1.1.0 <= 1.1.1"
-
Affected