CVE-2021-21264: October/cms Bypass Of Fix For CVE-2020-26231, Vulnerability
MODERATECVE-2021-21264 is a MODERATE (CVSS 5.2) bypass of fix for cve-2020-26231, vulnerability (CWE-862: Missing Authorization) affecting October/cms libraries in the Packagist ecosystem. The issue involves bypass of fix for cve-2020-26231, twig sandbox escape. Remediation is available by upgrading affected packages to version 1.0.472, 1.1.2.
CVE-2021-21264 at a Glance
Security Impact
CVSS: 5.2
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L).
How to Fix CVE-2021-21264
To remediate this vulnerability, upgrade all affected October/cms dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade october/cms to 1.0.472Upgrade october/cms to 1.1.2Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for october/cmsHow to Check if You Are Affected
To determine whether your application is affected by CVE-2021-21264, inspect your project dependencies for October/cms:
inspect dependencies for october/cmsAnalyze the terminal output to locate any version of October/cms in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.0.472), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-862: Missing Authorization, where the product does not perform an authorization check when an actor attempts to access a resource or perform an action. In October/cms, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2021-21264 Affected October/cms Versions
2 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
october/cms
|
Packagist |
≥ 1.0.471
< 1.0.472
All 1 versions
1.0.471
|
1.0.472
|
|
october/cms
|
Packagist |
≥ 1.1.1
< 1.1.2
All 1 versions
1.1.1
|
1.1.2
|
References
Frequently Asked Questions
What is CVE-2021-21264?
Which October/cms versions are affected?
What version fixes CVE-2021-21264?
Is october/cms affected?
What is the CVSS score of CVE-2021-21264?
What CWE is associated with CVE-2021-21264?
How can I check Packagist dependencies for CVE-2021-21264?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-fcr8-6q7r-m4wg",
"modified" : "2022-10-20T13:56:32Z",
"published" : "2021-05-04T17:42:33Z",
"aliases" : [ "CVE-2021-21264" ],
"summary" : "Bypass of fix for CVE-2020-26231, Twig sandbox escape",
"details" : "### Impact\nA 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:\n\nAn 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.\n\nThis 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.\n\n### Patches\nIssue has been patched in Build 472 (v1.0.472) and v1.1.2.\n\n### Workarounds\nApply https://github.com/octobercms/october/commit/f63519ff1e8d375df30deba63156a2fc97aa9ee7 to your installation manually if unable to upgrade to Build 472 or v1.1.2.\n\n### References\nReported by [ka1n4t](https://github.com/ka1n4t)\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Email us at [hello@octobercms.com](mailto:hello@octobercms.com)\n\n### Threat assessment:\n<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\">",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Packagist",
"name" : "october/cms"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "1.0.471"
}, {
"fixed" : "1.0.472"
} ]
} ],
"versions" : [ "1.0.471" ]
}, {
"package" : {
"ecosystem" : "Packagist",
"name" : "october/cms"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "1.1.1"
}, {
"fixed" : "1.1.2"
} ]
} ],
"versions" : [ "1.1.1" ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/octobercms/october/security/advisories/GHSA-fcr8-6q7r-m4wg"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-21264"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/octobercms/october"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-862" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2021-05-03T15:59:55Z",
"nvd_published_at" : "2021-05-03T16:15:00Z"
}
}