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Fencer Vulns
critical 9.8

CVE-2021-42669 in the critical feed json

A file upload vulnerability exists in Sourcecodester Engineers Online Portal in PHP via dashboard_teacher.php, which allows changing the av…

published 2021-11-05 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-29630

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
23.3%
EPSS 23.3% chance of exploitation in 30 days, percentile 97%
public exploits
0
none known

Summary

A file upload vulnerability exists in Sourcecodester Engineers Online Portal in PHP via dashboard_teacher.php, which allows changing the avatar through teacher_avatar.php. Once an avatar gets uploaded it is getting uploaded to the /admin/uploads/ directory, and is accessible by all users. By uploading a php webshell containing "<?php system($_GET["cmd"]); ?>" the attacker can execute commands on the web server with - /admin/uploads/php-webshell?cmd=id.

Exploit prediction

23.27% chance of exploitation in the next 30 days, higher than 97% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/TheHackingRabbi/CVE-2021-42669 referenced PoC, tagged "exploit" by a source, unverified
  • github.com https://github.com/nu11secur1ty/CVE-mitre/tree/main/CVE-2021-42671 referenced PoC, tagged "exploit" by a source, unverified

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 Vulns 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.