CVE-2021-39174Public exploitNetwork attack vector

Authenticated secret disclosure via nested dotenv variables

Published Aug 27, 2021 · Updated Aug 4, 2024

Configuration injection in Cachet 2.5.0 and earlier allows remote authenticated users to read dotenv secrets through the dashboard. UpdateConfigCommandHandler writes a ${NAME} placeholder into one setting, and phpdotenv expands it before the interface redisplays the value. Any basic User account can expose APP_KEY, database passwords, or mail passwords; no administrator role or user interaction is required.

CVSS severity8.8
High
EPSS probability5.01%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Configuration injection in Cachet 2.5.0 and earlier allows remote authenticated users to read dotenv secrets through the dashboard. UpdateConfigCommandHandler writes a ${NAME} placeholder into one setting, and phpdotenv expands it before the interface redisplays the value. Any basic User account can expose APP_KEY, database passwords, or mail passwords; no administrator role or user interaction is required.

The record

CVE
CVE-2021-39174
Published
Aug 27, 2021
Updated
Aug 4, 2024
Vendor
CachetHQ
Product
Cachet
Classifications
CWE-75, T1552.001
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 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 exploitPublished

Weakness, pattern, technique

CWE-75Failure to Sanitize Special Elements into a Different Plane (Special Element Injection)
T1552.001Unsecured Credentials: Credentials In Files

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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