CVE-2021-22969
Concrete CMS (formerly concrete5) versions below 8.5.7 has a SSRF mitigation bypass using DNS Rebind attack giving an attacker the ability to fetch cloud IAAS (ex AWS) IAM keys.To fix this Concrete CMS no longer allows downloads from the local network…
Does this matter?
Lower severity and a low EPSS score (0.86%). Track it; it rarely justifies an emergency change on its own.
Description
Concrete CMS (formerly concrete5) versions below 8.5.7 has a SSRF mitigation bypass using DNS Rebind attack giving an attacker the ability to fetch cloud IAAS (ex AWS) IAM keys.To fix this Concrete CMS no longer allows downloads from the local network and specifies the validated IP when downloading rather than relying on DNS.Discoverer: Adrian Tiron from FORTBRIDGE ( https://www.fortbridge.co.uk/ )The Concrete CMS team gave this a CVSS 3.1 score of 3.5 AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N . Please note that Cloud IAAS provider mis-configurations are not Concrete CMS vulnerabilities. A mitigation for this vulnerability is to make sure that the IMDS configurations are according to a cloud provider's best practices.This fix is also in Concrete version 9.0.0
- CVSS 3.1
- 5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- EPSS
- 0.86% probability · 56th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-918
- Affected
- concretecms/concrete cms
- Source
- support@hackerone.com
References
- https://documentation.concretecms.org/developers/introduction/version-history/857-release-notesRelease Notes, Vendor Advisory
- https://hackerone.com/reports/1369312Permissions Required
- https://documentation.concretecms.org/developers/introduction/version-history/857-release-notesRelease Notes, Vendor Advisory
- https://hackerone.com/reports/1369312Permissions Required
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.