#VU105694 Input validation error in FortiWeb - CVE-2023-42784

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Main Vulnerability Database Vulnerabilities #VU105694

#VU105694 Input validation error in FortiWeb - CVE-2023-42784

Published: March 13, 2025


Vulnerability identifier: #VU105694
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2023-42784
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability: No public exploit available
Vulnerable software:
FortiWeb
Software vendor:
Fortinet, Inc

Description

The vulnerability allows a remote attacker to bypass firewall protection.

The vulnerability exists due to insufficient validation of files. A remote attacker can send a specially crafted HTTP request with an empty filename and bypass implemented firewall rules.


Remediation

Install updates from vendor's website.

MANDATORY steps to enable the fix :

  1. Update to the latest FDS version

  2. Approve signature 050240001

  3. Enable signature policy in corresponding Web Protection Profile, "Say Standard Protection"

  4. Go to Web Protection/Input Validation/File Security/File Security Rule

  5. Click Create New, set name to "file_security"

  6. In "Request URL Type" choose "Regular Expression" in "Request URL"

  7. Add "/" Click "OK"

  8. Go to Web Protection/Input Validation/File Security/File Security Policy

  9. Click Create New

  10. Set a name say file_test

  11. Enable "Signature Detection", Click "OK"

  12. Click "Create New", Select the above added "File Security Rule", Click "OK"

  13. In CLI :

'''
Config waf http-protocol-parameter-restriction

edit "hpc1"

set chunk-size-action alert_deny

set chunk-size-severity High

next

end

'''



External links