Ecosyste.ms: Advisories

Security Advisories: MDE2OlNlY3VyaXR5QWR2aXNvcnlHSFNBLWg3NnItdmdmMy1qNnc1

October CMS auth bypass and account takeover

Impact

An attacker can exploit this vulnerability to bypass authentication using a specially crafted persist cookie.

• To exploit this vulnerability, an attacker must obtain a Laravel’s secret key for cookie encryption and signing.
• Due to the logic of how this mechanism works, a targeted user account must be logged in while
  the attacker is exploiting the vulnerability.
• Authorization via persist cookie not shown in access logs.

Patches

• Issue has been patched in Build 472 and v1.1.5
• Shortened patch instructions

Workarounds

Apply https://github.com/octobercms/library/commit/016a297b1bec55d2e53bc889458ed2cb5c3e9374 and https://github.com/octobercms/library/commit/5bd1a28140b825baebe6becd4f7562299d3de3b9 to your installation manually if you are unable to upgrade.

[Update 2022-01-20] Shortened patch instructions can be found here.

Recommendations

We recommend the following steps to make sure your server stays secure:

• Keep server OS and system software up to date.
• Keep October CMS software up to date.
• Use a multi-factor authentication plugin.
• Change the default backend URL or block public access to the backend area.
• Include the Roave/SecurityAdvisories Composer package to ensure that your application doesn't have installed dependencies with known security vulnerabilities.

References

Bugs found as part of Solar Security CMS Research. Credits to:
• Andrey Basarygin
• Andrey Guzei
• Mikhail Khramenkov
• Alexander Sidukov
• Maxim Teplykh

For more information

If you have any questions or comments about this advisory:

• Email us at [email protected]

Permalink: https://github.com/advisories/GHSA-h76r-vgf3-j6w5
JSON: https://advisories.ecosyste.ms/api/v1/advisories/MDE2OlNlY3VyaXR5QWR2aXNvcnlHSFNBLWg3NnItdmdmMy1qNnc1
Source: GitHub Advisory Database
Origin: Unspecified
Severity: High
Classification: General
Published: about 3 years ago
Updated: almost 2 years ago

CVSS Score: 7.4
CVSS vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Identifiers: GHSA-h76r-vgf3-j6w5, CVE-2021-29487
References:

• https://github.com/octobercms/october/security/advisories/GHSA-h76r-vgf3-j6w5
• https://github.com/octobercms/library/commit/016a297b1bec55d2e53bc889458ed2cb5c3e9374
• https://nvd.nist.gov/vuln/detail/CVE-2021-29487
• https://github.com/octobercms/library/commit/5bd1a28140b825baebe6becd4f7562299d3de3b9
• https://github.com/advisories/GHSA-h76r-vgf3-j6w5

Repository: https://github.com/octobercms/october
Blast Radius: 18.7

Affected Packages