CVE-2020-28906Known exploitationPublic exploit

Root code execution via writable sourced configuration

Published May 24, 2021 · Updated Aug 4, 2024

Incorrect file permissions in Nagios XI 5.7.5 and earlier and Nagios Fusion 4.1.8 and earlier allow local users to gain root access. The nagios account can modify xi-sys.cfg or fusion-sys.cfg, which privileged scripts source while executing as root. Access to the low-privileged nagios account is required; injected shell content then executes with full host control.

CVSS severity8.8
High
EPSS probability4.73%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect file permissions in Nagios XI 5.7.5 and earlier and Nagios Fusion 4.1.8 and earlier allow local users to gain root access. The nagios account can modify xi-sys.cfg or fusion-sys.cfg, which privileged scripts source while executing as root. Access to the low-privileged nagios account is required; injected shell content then executes with full host control.

The record

CVE
CVE-2020-28906
Published
May 24, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-276, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 20, 2021Exploitation reportedSoyGun Nagios compromise chain demonstration
  2. May 24, 2021CVE publishedPublication date reported by the CVE source.
  3. 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 vectorlocal
Required privilegesauthenticated

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
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/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.

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No observations available

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

Weakness, pattern, technique

CWE-276Incorrect Default Permissions
T1068Exploitation for Privilege Escalation

Public exploit references

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

Reported exploitation

Technologies

Your stack

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Your stack

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