CVE-2021-22968

Concrete Cms vulnerability

CVSS

7.2

EPSS

3.1%

EPSS pct

87th

Exploited

No known

A bypass of adding remote files in Concrete CMS (previously concrete5) File Manager leads to remote code execution in Concrete CMS (concrete5) versions 8.5.6 and below.The external file upload feature stages files in the public directory even if they have disallowed file extensions. They are stored in a directory with a random name, but it's possible to stall the uploads and brute force the directory name. You have to be an admin with the ability to upload files, but this bug gives you the ability to upload restricted file types and execute them depending on server configuration.To fix this, a check for allowed file extensions was added before downloading files to a tmp directory.Concrete CMS Security Team gave this a CVSS v3.1 score of 5.4 AV:N/AC:H/PR:H/UI:R/S:C/C:N/I:H/A:NThis fix is also in Concrete version 9.0.0

Affected vendor

Concretecms

Affected product

Concrete Cms

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Weakness type (CWE)

CWE-98 — PHP Remote File Inclusion
CWE-330 — Use of Insufficiently Random Values
CWE-434 — Unrestricted Upload of File with Dangerous Type

Published

2021-11-19

Risk analysis

Based on its CVSS vector, this vulnerability is exploitable over the network, low attack complexity, requiring high privileges, no user interaction. Successful exploitation leads to high impact to confidentiality, high impact to integrity, high impact to availability.

Its EPSS score of 3.1% reflects a lower probability of exploitation activity in the wild over the next 30 days, placing it above 87% of all scored CVEs.

Check your external exposure to CVE-2021-22968

Confirm whether Concretecms Concrete Cms is running on any internet-facing host or subdomain.
Match discovered service fingerprints against the version affected by CVE-2021-22968.
Prioritise remediation if the asset is public, business-critical, or near authentication/payment flows.

How ThreatPort helps with CVE-2021-22968

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