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

• CVE ID
• CVE-2021-22969

• Assigner
• support@hackerone.com

• Vulnerability Status
• Analyzed

• Published Version
• 2021-11-19T19:15:08

• Last Modified Date
• 2021-11-23T13:35:11

• Version
• 2.0

• Vector String
• AV:N/AC:L/Au:N/C:P/I:N/A:N

• Access Vector
• NETWORK

• Access Compatibility
• LOW

• Authentication
• NONE

• Confidentiality Impact
• PARTIAL

• Integrity Impact
• NONE

• Availability Impact
• NONE

• Base Score
• 5

• Severity
• MEDIUM

• Exploitability Score
• 10

• Impact Score
• 2.9

• Version
• 3.1

• Vector String
• CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

• Attack Vector
• NETWORK

• Attack Compatibility
• LOW

• Privileges Required
• NONE

• User Interaction
• NONE

• Scope
• UNCHANGED

• Confidentiality Impact
• LOW

• Availability Impact
• NONE

• Base Score
• 5.3

• Base Severity
• MEDIUM

• Exploitability Score
• 3.9

• Impact Score
• 1.4