CVE-2020-26231 Bypass of fix for CVE-2020-15247, Twig sandbox escape
Authenticated users can bypass Twig sandbox restrictions to execute arbitrary PHP code if safe mode is enabled.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2020-26231?
CVE-2020-26231 is a medium-severity code injection vulnerability in Octobercms October, published on 23 Nov 2020. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
October is a free, open-source, self-hosted CMS platform based on the Laravel PHP Framework. 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. Issue has been patched in Build 470 (v1.0.470) and v1.1.1.
Weakness: CWE-862
Which versions are affected by CVE-2020-26231?
2 open source packages ship an affected version, including october/cms. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
october/cms Packagist | From 1.0.469 | 1.0.470 |
october/cms Packagist | From 1.0.469 | 1.0.470 |
Products include Octobercms October.
How do I fix CVE-2020-26231?
Upgrade october/cms to 1.0.470 or later.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2020-26231 being exploited?
There is no known exploitation of CVE-2020-26231 in the wild and no public exploit code.
Other vulnerabilities in Octobercms October
Sources
Also known as GHSA-r89v-cgv7-3jhx.