Low

Bypass of fix for CVE-2020-15247, Twig sandbox escape

  • Disclosed: 23.11.2020
  • Updated: 11.10.2026 10:22

Impact

A bypass of CVE-2020-15247 (fixed in 1.0.469 and 1.1.0) was discovered that has the same impact as 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.

Patches

Issue has been patched in Build 470 (v1.0.470) and v1.1.1.

Workarounds

Apply https://github.com/octobercms/october/commit/d34fb8ab51108495a9a651b841202d935f4e12f7 to your installation manually if unable to upgrade to Build 470 or v1.1.1.

References

Reported by ka1n4t

For more information

If you have any questions or comments about this advisory:

Threat assessment:

<img width="1108" alt="Screen Shot 2020-10-10 at 1 21 13 PM" src="https://user-images.githubusercontent.com/7253840/95663316-7de28b80-0afb-11eb-999d-a6526cf78709.png">

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Composer package october/cms >= 1.0.469, < 1.0.470 1.0.470

References

CVSS score 5.2/10
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L
Weakness (CWE)
CWE-862
Platform
Composer
Package
october/cms
Disclosed
23.11.2020
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-r89v-cgv7-3jhx - CC BY 4.0

Vulnerability history: october/cms

All published vulnerabilities of this package (Composer package), newest first. Shows whether this is a one-off slip or a package that needs watching.

Total entries
8
First → latest
06.2020 05.2022
Without a fix
1
Exploited in attacks
0

Severity breakdown

  • High 2
  • Medium 4
  • Low 2

Disclosures per year

  1. 2020: 6
  2. 2021: 1
  3. 2022: 1
  4. 2023: 0
  5. 2024: 0
  6. 2025: 0
  7. 2026: 0
  1. High · 7.2 CVE-2017-1000119 <= 1.0.412 no fix
  2. Medium · 5.2 CVE-2021-21264 >= 1.0.471, < 1.0.472, >= 1.1.1, < 1.1.2 1.0.472, 1.1.2
  3. Bypass of fix for CVE-2020-15247, Twig sandbox escape this entry
    Low · 5.2 CVE-2020-26231 >= 1.0.469, < 1.0.470 1.0.470
  4. High · 7.5 CVE-2020-15246 >= 1.0.421, < 1.0.469 1.0.469
  5. Low · 3.4 CVE-2020-5297 >= 1.0.319, < 1.0.466 1.0.466
  6. Medium · 6.2 CVE-2020-5296 >= 1.0.319, < 1.0.466 1.0.466
  7. Medium · 4.8 CVE-2020-5295 >= 1.0.319, < 1.0.466 1.0.466

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