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githubGitHub Advisory DatabaseGHSA-FCR8-6Q7R-M4WG
HistoryMay 04, 2021 - 5:42 p.m.

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

2021-05-0417:42:33
CWE-862
GitHub Advisory Database
github.com
49

4.4 Medium

CVSS2

Attack Vector

LOCAL

Attack Complexity

MEDIUM

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

PARTIAL

Availability Impact

PARTIAL

AV:L/AC:M/Au:N/C:P/I:P/A:P

6.7 Medium

CVSS3

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

HIGH

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

0.0004 Low

EPSS

Percentile

12.6%

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:

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 configurations

Vulners
Node
octobercmsMatch1.1.1
OR
octobercmsMatch1.0.471
CPENameOperatorVersion
october/cmseq1.1.1
october/cmseq1.0.471

4.4 Medium

CVSS2

Attack Vector

LOCAL

Attack Complexity

MEDIUM

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

PARTIAL

Availability Impact

PARTIAL

AV:L/AC:M/Au:N/C:P/I:P/A:P

6.7 Medium

CVSS3

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

HIGH

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

0.0004 Low

EPSS

Percentile

12.6%

Related for GHSA-FCR8-6Q7R-M4WG