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Fencer Intel
critical 9.8

CVE-2021-36582 json

In Kooboo CMS 2.1.1.0, it is possible to upload a remote shell (e.g., aspx) to the server and then call upon it to receive a reverse shell…

published 5y ago modified 4mo ago also EUVD-2021-23179

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.5%
EPSS 1.5% chance of exploitation in 30 days, percentile 74%
public exploits
0
none known

Summary

In Kooboo CMS 2.1.1.0, it is possible to upload a remote shell (e.g., aspx) to the server and then call upon it to receive a reverse shell from the victim server. The files are uploaded to /Content/Template/root/reverse-shell.aspx and can be simply triggered by browsing that URL.

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Exploit prediction

1.48% chance of exploitation in the next 30 days, higher than 74% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 10.0 AV:N/AC:L/Au:N/C:C/I:C/A:C

Classification

Weakness
  • CWE-434 Unrestricted Upload of File with Dangerous Type

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.