CVE-2021-22967Network attack vector

Restricted file access via unchecked attachment authorization

Published Nov 19, 2021 · Updated Aug 3, 2024

Authorization bypass in Concrete CMS 8.5.6 and earlier allows remote attackers to access restricted files via conversation messages. The message add/edit flow attaches user-supplied file references without checking whether the requester may view each file, creating an IDOR. Reachability requires permission to add a conversation message, and the demonstrated consequence is unauthorized file disclosure without reported modification or service interruption.

CVSS severity4.3
Medium
EPSS probability1.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authorization bypass in Concrete CMS 8.5.6 and earlier allows remote attackers to access restricted files via conversation messages. The message add/edit flow attaches user-supplied file references without checking whether the requester may view each file, creating an IDOR. Reachability requires permission to add a conversation message, and the demonstrated consequence is unauthorized file disclosure without reported modification or service interruption.

The record

CVE
CVE-2021-22967
Published
Nov 19, 2021
Updated
Aug 3, 2024
Vendor
Concrete CMS
Product
Concrete CMS
Classifications
CWE-639
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 19, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Affected version - Concrete 8.5.6 and below. Fixed version 9.0 and 8.5.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Concrete CMS · Concrete CMSversion=Affected version - Concrete 8.5.6 and below. Fixed version 9.0 and 8.5.7

Published CVSS scores

4.3Concrete CMS Security TeamCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
5.0NVDAV:N/AC:L/Au:N/C:P/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-639Authorization Bypass Through User-Controlled Key

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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