CVE-2021-25294

Name: CVE-2021-25294
Creator: NVD / NIST
Published: 2021-01-18T06:15:12.897+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 10.68%

Last modified Jun 17, 2026

CVE-2021-25294 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. OpenCATS through 0.9.5-3 unsafely deserializes index.php?m=activity requests, leading to remote code execution. This occurs because lib/DataGrid.php calls unserialize for the parametersactivity:ActivityDataGrid parameter. EPSS estimates a 10.68% chance of exploitation in the next 30 days.

Description

OpenCATS through 0.9.5-3 unsafely deserializes index.php?m=activity requests, leading to remote code execution. This occurs because lib/DataGrid.php calls unserialize for the parametersactivity:ActivityDataGrid parameter. The PHP object injection exploit chain can leverage an __destruct magic method in guzzlehttp.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

10.68%

95.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-502

Affected Software

Vendor	Product	Versions
Opencats	Opencats	<= 0.9.5-3

References

https://github.com/snoopysecurity/snoopysecurity.github.io/blob/master/web-application-security/2021/01/16/09_opencats_php_object_injection.htmlPatch, Third Party Advisory
https://snoopysecurity.github.io/web-application-security/2021/01/16/09_opencats_php_object_injection.htmlExploit, Third Party Advisory
https://www.opencats.org/news/Vendor Advisory
https://github.com/snoopysecurity/snoopysecurity.github.io/blob/master/web-application-security/2021/01/16/09_opencats_php_object_injection.htmlPatch, Third Party Advisory
https://snoopysecurity.github.io/web-application-security/2021/01/16/09_opencats_php_object_injection.htmlExploit, Third Party Advisory
https://www.opencats.org/news/Vendor Advisory

Timeline

Published: Jan 18, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-25294?

How severe is CVE-2021-25294?

CVE-2021-25294 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 10.68% probability of exploitation in the next 30 days.

How do I fix CVE-2021-25294?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-25294?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST