Bypass of fix for CVE-2020-26231, Twig sandbox escape
The advisory, in context
Impact
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.
Patches
Issue has been patched in Build 472 (v1.0.472) and v1.1.2.
Workarounds
Apply https://github.com/octobercms/october/commit/f63519ff1e8d375df30deba63156a2fc97aa9ee7 to your installation manually if unable to upgrade to Build 472 or v1.1.2.
References
Reported by ka1n4t
For more information
If you have any questions or comments about this advisory:
- Email us at hello@octobercms.com
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 packages
Start with the recorded fix for your release branch. Check your installed version and test compatibility before upgrading. Fixing this advisory does not rule out other vulnerabilities in the release.
From 1.0.471 before 1.0.472
Fixed in 1.0.472
2 explicitly affected versions
1.0.471, v1.0.471
View affected-version evidence
{
"ranges": [
{
"events": [
{
"introduced": "1.0.471"
},
{
"fixed": "1.0.472"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.0.471",
"v1.0.471"
]
}From 1.1.1 before 1.1.2
Fixed in 1.1.2
2 explicitly affected versions
1.1.1, v1.1.1
View affected-version evidence
{
"ranges": [
{
"events": [
{
"introduced": "1.1.1"
},
{
"fixed": "1.1.2"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.1.1",
"v1.1.1"
]
}