CVE-2021-39173
Forced reinstall
Cachet is an open source status page system. Prior to version 2.5.1 authenticated users, regardless of their privileges (User or Admin), can trick Cachet and install the instance again, leading to arbitrary code execution on the server. This issue was addressed in version 2.5.1 by improving the middleware ReadyForUse, which now performs a stricter validation of the instance name. As a workaround, only allow trusted source IP addresses to access to the administration dashboard.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Forced reinstall
Cachet is an open source status page system. Prior to version 2.5.1 authenticated users, regardless of their privileges (User or Admin), can trick Cachet and install the instance again, leading to arbitrary code execution on the server. This issue was addressed in version 2.5.1 by improving the middleware ReadyForUse, which now performs a stricter validation of the instance name. As a workaround, only allow trusted source IP addresses to access to the administration dashboard.
- Record
CVE-2021-39173- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-704
- Updated
- 2026-11-02
EUVDEUVD-2021-1857
Cachet is an open source status page system. Prior to version 2.5.1 authenticated users, regardless of their privileges (User or Admin), can trick Cachet and install the instance again, leading to arbitrary code execution on the server. This issue was addressed in version 2.5.1 by improving the middleware ReadyForUse, which now performs a stricter validation of the instance name. As a workaround, only allow trusted source IP addresses to access to the administration dashboard.
- Record
EUVD-2021-1857- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-r67m-m8c7-jp83
Cachet vulnerable to forced reinstall
Impact
Authenticated users, regardless of their privileges (User or Admin), can trick Cachet and install the instance again, leading to arbitrary code execution on the server.
Patches
This issue was addressed by improving the middleware ReadyForUse, which now performs a stricter validation of the instance name.
Workarounds
Only allow trusted source IP addresses to access to the administration dashboard.
References
For more information
If you have any questions or comments about this advisory, you can contact:
- The original reporters, by sending an email to vulnerability.research [at] sonarsource.com;
- The maintainers, by opening an issue on this repository.
- Record
GHSA-r67m-m8c7-jp83- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-704
- Updated
- 2026-11-02
NVD
Cachet is an open source status page system. Prior to version 2.5.1 authenticated users, regardless of their privileges (User or Admin), can trick Cachet and install the instance again, leading to arbitrary code execution on the server. This issue was addressed in version 2.5.1 by improving the middleware ReadyForUse, which now performs a stricter validation of the instance name. As a workaround, only allow trusted source IP addresses to access to the administration dashboard.
- Record
CVE-2021-39173- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 6.5 Medium
AV:N/AC:L/Au:S/C:P/I:P/A:P - Weakness
- CWE-704
- Updated
- 2026-11-02
OSV
Cachet is an open source status page system. Prior to version 2.5.1 authenticated users, regardless of their privileges (User or Admin), can trick Cachet and install the instance again, leading to arbitrary code execution on the server. This issue was addressed in version 2.5.1 by improving the middleware ReadyForUse, which now performs a stricter validation of the instance name. As a workaround, only allow trusted source IP addresses to access to the administration dashboard.
- Record
CVE-2021-39173- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVGHSA-r67m-m8c7-jp83
Cachet vulnerable to forced reinstall
Impact
Authenticated users, regardless of their privileges (User or Admin), can trick Cachet and install the instance again, leading to arbitrary code execution on the server.
Patches
This issue was addressed by improving the middleware ReadyForUse, which now performs a stricter validation of the instance name.
Workarounds
Only allow trusted source IP addresses to access to the administration dashboard.
References
For more information
If you have any questions or comments about this advisory, you can contact:
- The original reporters, by sending an email to vulnerability.research [at] sonarsource.com;
- The maintainers, by opening an issue on this repository.
- Record
GHSA-r67m-m8c7-jp83- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-704
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
cachethq/cachetPackagist |
before 2.5.1 | 2.5.1 |
cachethq/cachetPackagist |
before 2.5.1, plus listed versions v0.1.0-alphav1.0.0v1.1.0v1.1.1v1.2.0 Show 45 moreShow lessv1.2.1v2.0.0v2.0.0-RC1v2.0.0-RC2v2.0.0-RC3v2.0.0-RC4v2.0.0-RC5v2.0.0-beta1v2.0.0-beta2v2.0.1v2.0.2v2.0.3v2.0.4v2.1.0v2.1.0-RC1v2.1.0-RC2v2.1.1v2.1.2v2.2.0v2.2.0-RC1v2.2.1v2.2.2v2.2.3v2.2.4v2.3.0v2.3.0-RC1v2.3.0-RC2v2.3.0-RC3v2.3.0-RC4v2.3.0-RC5v2.3.0-RC6v2.3.1v2.3.10v2.3.11v2.3.12v2.3.13v2.3.14v2.3.15v2.3.16v2.3.17v2.3.18v2.3.2v2.3.3v2.3.4v2.3.5 |
2.5.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, products | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-39173 is a high vulnerability (CVSS 8.8) in Cachethq Cachet, published August 27, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.36%, the 83rd percentile. Fixed in cachethq/cachet 2.5.1.
References
Left out here: 6 versions. The JSON record has them.