CVE-2021-40345Public exploitNetwork attack vector

Administrator command execution via crafted archive filename

Published Oct 26, 2021 · Updated Aug 4, 2024

Command injection in Nagios XI 5.8.3 through 5.8.5 allows remote authenticated users with administrator access to execute system commands. The cmdsubsys.php dashlet installer reads the first extracted filename, concatenates it unescaped into a grep command, and passes the result to PHP system(). Access to the Manage Dashlets administrator panel and a crafted ZIP archive are required; commands run as the nagios account.

CVSS severity7.2
High
EPSS probability22.69%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Command injection in Nagios XI 5.8.3 through 5.8.5 allows remote authenticated users with administrator access to execute system commands. The cmdsubsys.php dashlet installer reads the first extracted filename, concatenates it unescaped into a grep command, and passes the result to PHP system(). Access to the Manage Dashlets administrator panel and a crafted ZIP archive are required; commands run as the nagios account.

The record

CVE
CVE-2021-40345
Published
Oct 26, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-77, T1059.004
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Oct 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.0NIST NVDAV:N/AC:L/Au:S/C:C/I:C/A:C
7.2NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

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 exploitPublished

Weakness, pattern, technique

CWE-77Improper Neutralization of Special Elements used in a Command ('Command Injection')
T1059.004Command and Scripting Interpreter: Unix Shell

Public exploit references

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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