SSRF in Concretecms Concrete Cms
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 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
Vulnerability class: SSRF (Server-Side Request Forgery)
EPSS: 0.008 (53.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
Affected products
- Concretecms Concrete_cms
- N/a Https://github.com/concrete5/concrete5 — versions Affected version Concrete CMS (concrete5) 8.5.6 and below. Fixed in Concrete CMS version 8.5.7 and 9.0.0
Weakness classification (CWE)
References
- support@hackerone.com (Permissions Required, x_refsource_MISC)
- support@hackerone.com (x_refsource_MISC, Release Notes, Vendor Advisory)
Frequently asked questions
- What is CVE-2021-22969?
- CVE-2021-22969 is a medium-severity vulnerability in Concretecms Concrete Cms, classified under Server-Side Request Forgery (SSRF). CVSS score: 5.3/10. Published 2021-11-19.
- How severe is CVE-2021-22969?
- Medium severity. CVSS v3 base score is 5.3 out of 10.