CVE-2021-42756

CRITICAL

Fortinet Fortiweb < 6.0.8 - Out-of-Bounds Write

Title source: rule

Description

Multiple stack-based buffer overflow vulnerabilities [CWE-121] in the proxy daemon of FortiWeb 5.x all versions, 6.0.7 and below, 6.1.2 and below, 6.2.6 and below, 6.3.16 and below, 6.4 all versions may allow an unauthenticated remote attacker to achieve arbitrary code execution via specifically crafted HTTP requests.

Exploits (1)

nomisec WORKING POC

by 3ndorph1n · poc

https://github.com/3ndorph1n/CVE-2021-42756

View Code ZIP pw:eip

References (1)

[Vendor Advisory] https://fortiguard.com/psirt/FG-IR-21-186

Scores

CVSS v3 9.8

EPSS 0.6422

EPSS Percentile 98.5%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment

Exploitation none

Automatable yes

Technical Impact total

Details

CWE

CWE-121 CWE-787

Status published

Products (1)

fortinet/fortiweb 5.6.0 - 6.0.8

Published Feb 16, 2023

Tracked Since Feb 18, 2026