CVE-2021-20682Network attack vector

Admin command execution via malicious plugin upload

Published Mar 26, 2021 · Updated Aug 3, 2024

OS command injection in baserCMS before 4.4.5 allows remote authenticated administrators to execute arbitrary OS commands via plugin uploads. The administrative plugin uploader accepts a malicious plugin, but the vendor does not disclose the exact command construction or neutralization failure. Administrator access to the web interface is required, and successful exploitation runs attacker-supplied commands with the web service account's privileges.

CVSS severity7.2
High
EPSS probability2.48%
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 before 4.4.5 allows remote authenticated administrators to execute arbitrary OS commands via plugin uploads. The administrative plugin uploader accepts a malicious plugin, but the vendor does not disclose the exact command construction or neutralization failure. Administrator access to the web interface is required, and successful exploitation runs attacker-supplied commands with the web service account's privileges.

The record

CVE
CVE-2021-20682
Published
Mar 26, 2021
Updated
Aug 3, 2024
Vendor
baserCMS Users Community
Product
baserCMS
Classifications
CWE-78, CAPEC-88, T1059
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Mar 26, 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=versions prior to 4.4.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

baserCMS Users Community · baserCMSversion=versions prior to 4.4.5

Published CVSS scores

7.2NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
7.2JVNCVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
6.5JVNAV:N/AC:L/Au:S/C:P/I:P/A:P

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CAPEC-88OS 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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