CVE-2021-41243Network attack vector

Authenticated command execution via unvalidated preview template

Published Nov 26, 2021 · Updated Aug 4, 2024

OS command injection in baserCMS 4.5.3 and earlier allows remote authenticated users to execute host commands through fixed-page preview. PagesController::display writes attacker-controlled contents_tmp data into a temporary PHP view and renders it without first rejecting executable PHP content. Access to the management interface and fixed-page editing is required, and commands run with the web server process privileges.

CVSS severity9.1
Critical
EPSS probability2.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in baserCMS 4.5.3 and earlier allows remote authenticated users to execute host commands through fixed-page preview. PagesController::display writes attacker-controlled contents_tmp data into a temporary PHP view and renders it without first rejecting executable PHP content. Access to the management interface and fixed-page editing is required, and commands run with the web server process privileges.

The record

CVE
CVE-2021-41243
Published
Nov 26, 2021
Updated
Aug 4, 2024
Vendor
baserCMS Users Community
Product
baserCMS
Classifications
CWE-78, T1059
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 26, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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=< 4.5.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

baserCMS Users Community · baserCMSversion=< 4.5.4

Published CVSS scores

9.1GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
9.0NIST NVDAV:N/AC:L/Au:S/C:C/I:C/A:C

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-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059Command and Scripting Interpreter

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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