Skip to content
Fencer Intel
high 8.8

CVE-2020-12255 in the critical feed json

rConfig 3.9.4 is vulnerable to remote code execution due to improper validation in the file upload functionality.

published 6y ago modified 4mo ago also EUVD-2020-4569

cvss
8.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
58.1%
EPSS 58.1% chance of exploitation in 30 days, percentile 99%
public exploits
0
none known

Summary

rConfig 3.9.4 is vulnerable to remote code execution due to improper validation in the file upload functionality. vendor.crud.php accepts a file upload by checking content-type without considering the file extension and header. Thus, an attacker can exploit this by uploading a .php file to vendor.php that contains arbitrary PHP code and changing the content-type to image/gif.

Is CVE-2020-12255 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Exploit prediction

58.09% chance of exploitation in the next 30 days, higher than 99% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 6.5 AV:N/AC:L/Au:S/C:P/I:P/A:P

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.