CVE-2021-39173Public exploitNetwork attack vector

Authenticated code execution via false instance name

Published Aug 27, 2021 · Updated Aug 4, 2024

Incorrect type conversion in Cachet before 2.5.1 allows remote authenticated users to execute arbitrary code by forcing reinstallation. The SetupAlreadyCompleted middleware treats a false-equivalent app_name value written by SettingsController as proof that setup is incomplete. Any basic user account can reopen /setup, replace the database and administrator account, and run server-side code.

CVSS severity8.8
High
EPSS probability2.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect type conversion in Cachet before 2.5.1 allows remote authenticated users to execute arbitrary code by forcing reinstallation. The SetupAlreadyCompleted middleware treats a false-equivalent app_name value written by SettingsController as proof that setup is incomplete. Any basic user account can reopen /setup, replace the database and administrator account, and run server-side code.

The record

CVE
CVE-2021-39173
Published
Aug 27, 2021
Updated
Aug 4, 2024
Vendor
CachetHQ
Product
Cachet
Classifications
CWE-704, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 27, 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=< 2.5.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

CachetHQ · Cachetversion=< 2.5.1

Published CVSS scores

6.5NIST NVDAV:N/AC:L/Au:S/C:P/I:P/A:P
8.8GitHub, Inc.CVSS: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-704Incorrect Type Conversion or Cast
T1190Exploit Public-Facing Application

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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