CVE-2021-22969

MEDIUM

Concrete CMS < 8.5.7 - Server-Side Request Forgery via DNS Rebind Attack

Title source: llm
STIX 2.1

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

References (2)

Core 2
Core References
Permissions Required x_refsource_misc
https://hackerone.com/reports/1369312

Scores

CVSS v3 5.3
EPSS 0.0083
EPSS Percentile 53.0%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Details

CWE
CWE-918
Status published
Products (2)
concrete5/core 0 - 8.5.7Packagist
concretecms/concrete_cms < 8.5.7
Published Nov 19, 2021
Tracked Since Feb 18, 2026