CVE intelligence and bounded remediation

CVE-2021-42669 — Engineers Online Portal Project Engineers Online Portal security vulnerability

Critical CVSS 9.8

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.

Severity
Critical
CVSS
9.8 (3.1)
Published
2021-11-05
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-434

Affected products

  • engineers_online_portal_project / engineers_online_portal

Matched remediation archetype

Path traversal, unsafe upload, and file handling

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace untrusted filenames, archive entries, URLs, and path segments into read, write, include, extraction, and upload operations.
  • Identify filesystem roots, mount permissions, symbolic-link behavior, archive handling, and whether uploaded content is web-accessible or executable.
  • Review canonicalization and containment checks across supported operating systems and storage backends.

Remediate safely

  • Generate server-side storage identifiers and resolve paths beneath a fixed root using filesystem-aware containment checks.
  • Reject absolute, parent-relative, alternate-separator, device, link, and archive entries that escape the intended root.
  • Store uploads outside executable or served paths, validate type and size, and use private atomic temporary files.

Authoritative sources

Complete CVE record and remediation plan

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