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Vulnerability record · CVE-2021-25294 · published 18 January 2021

CVE-2021-25294: Opencats deserialization of untrusted data vulnerability

Opencats · Opencats

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.

9.8 CVSS 3.1 Critical EPSS 11% · top 4.3% CWE-502 · Deserialization of untrusted data
9.8CVSS 3.1 base score, v2 10.0
11%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
6References, 2 tagged exploit
17 Jun 2026Last modified by NVD

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.

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/snoopysecurity/snoopysecurity.github.io/blob/master/web-application-security/2021/01/16/09_opencats_p PatchThird Party Advisory
https://snoopysecurity.github.io/web-application-security/2021/01/16/09_opencats_php_object_injection.html ExploitThird 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_p PatchThird Party Advisory
https://snoopysecurity.github.io/web-application-security/2021/01/16/09_opencats_php_object_injection.html ExploitThird Party Advisory
https://www.opencats.org/news/ Vendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2022-48011Opencats sql injection vulnerabilityOpencats v0.9.7 was discovered to contain a SQL injection vulnerability via the importID parameter in the Import viewerrors function.EPSS 1.1%9.8CVE-2022-43019Opencats deserialization of untrusted data vulnerabilityOpenCATS v0.9.6 was discovered to contain a remote code execution (RCE) vulnerability via the getDataGridPager's ajax functionality.EPSS 2.1%9.8CVE-2021-41560Opencats unrestricted file upload vulnerabilityOpenCATS through 0.9.6 allows remote attackers to execute arbitrary code by uploading an executable file via lib/FileUtility.php.EPSS 11%7.5CVE-2019-13358Opencats xml external entity (xxe) vulnerabilitylib/DocumentToText.php in OpenCats before 0.9.4-3 has XXE that allows remote users to read files on the underlying operating system. The attacker mus…EPSS 24%6.5CVE-2022-43023Opencats sql injection vulnerabilityOpenCATS v0.9.6 was discovered to contain a SQL injection vulnerability via the importID parameter in the Import viewerrors function.EPSS 0.86%6.5CVE-2022-43020Opencats sql injection vulnerabilityOpenCATS v0.9.6 was discovered to contain a SQL injection vulnerability via the tag_id variable in the Tag update function.EPSS 0.86%6.5CVE-2022-43021Opencats sql injection vulnerabilityOpenCATS v0.9.6 was discovered to contain a SQL injection vulnerability via the entriesPerPage variable.EPSS 0.86%6.5CVE-2022-43022Opencats sql injection vulnerabilityOpenCATS v0.9.6 was discovered to contain a SQL injection vulnerability via the tag_id variable in the Tag deletion function.EPSS 0.86%

Source: NIST National Vulnerability Database (record CVE-2021-25294), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.