CVE-2021-22969

Summary

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

Affected Software

VendorProductVersion RangeStatus
n/ahttps://github.com/concrete5/concrete5Affected version Concrete CMS (concrete5) 8.5.6 and below. Fixed in Concrete CMS version 8.5.7 and 9.0.0affected

Weaknesses

  • CWE-918: Server-Side Request Forgery (SSRF) (CWE-918)

ADP Enrichment

CVE Program Container

Additional References

References