KEVIntel
9.2
CVSS
Critical

CVE-2023-27997

PUBLISHED

A heap-based buffer overflow vulnerability [CWE-122] in FortiOS version 7.2.4 and below, version 7.0.11 and below, version 6.4.12 and below,...

Exploited in the wild Used in malware Remote Low complexity No user interaction
Vendor
Fortinet
Product
FortiOS-6K7K, FortiProxy, FortiOS
Published
Jun 13, 2023
EPSS

Description

A heap-based buffer overflow vulnerability [CWE-122] in FortiOS version 7.2.4 and below, version 7.0.11 and below, version 6.4.12 and below, version 6.0.16 and below and FortiProxy version 7.2.3 and below, version 7.0.9 and below, version 2.0.12 and below, version 1.2 all versions, version 1.1 all versions SSL-VPN may allow a remote attacker to execute arbitrary code or commands via specifically crafted requests.

ios cisa malware ransomware edge nessus_scanner

CVSS scores

CVSS v3.1 9.2 Critical

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:F/RL:X/RC:R

Exploitation status

Exploited in the wild

Recorded 2023-06-13 00:00:00 UTC · Source

Used in malware

Recorded 2023-06-13 00:00:00 UTC · Source

SSVC decision points

Exploitation
active
Automatable
Yes
Technical impact
total

Known exploited vulnerability sources

Catalogues that list this CVE as a known exploited vulnerability.

Source Added
CISA Jun 13, 2023

Scanner integrations

Scanner Reference Detected
Nessus https://www.tenable.com/plugins/nessus/177116 Jun 02, 2025

Recent mentions

CVE-2025-32756: Zero-Day Vulnerability in Multiple Fortinet Products Exploited in the Wild

Tenable Blog · May 14, 2025

Fortinet has observed threat actors exploiting CVE-2025-32756, a critical zero-day arbitrary code execution vulnerability which affects multiple Fortinet products including FortiVoice, FortiMail, FortiNDR, FortiRecorder and FortiCamera.BackgroundOn May 13th, Fortinet published a security advisory (FG-IR-25-254) for CVE-2025-32756, a critical arbitrary code execution vulnerability affecting multiple Fortinet products.CVEDescriptionCVSSv3CVE-2025-32756An arbitrary code execution vulnerability in FortiVoice, FortiMail, FortiNDR, FortiRecorder and FortiCamera9.6AnalysisCVE-2025-32756 is an arbitrary code execution vulnerability affecting multiple Fortinet products including FortiVoice, FortiMail, FortiNDR, FortiRecorder and FortiCamera. A remote unauthenticated attacker can send crafted HTTP requests in order to create a stack-based overflow condition which would allow for the execution of arbitrary code. This vulnerability was discovered by the Fortinet Product Security Team who observed threat activity involving a device running FortiVoice.According to Fortinet, the threat actors operations included scanning the network, erasing system crashlogs and enabling ‘fcgi debugging’ which is used to log authentication attempts, including SSH logins. The ‘fcgi debugging’ option is not enabled by default and the Fortinet advisory recommends reviewing the setting as one possible indicator of compromise (IoC).Historical Exploitation of Fortinet DevicesFortinet vulnerabilities have historically been common targets for cyber attackers, and CVE-2025-32756 is the eighteenth Fortinet vulnerability to be added to the Cybersecurity and Infrastructure Security Agency’s (CISA) Known Exploited Vulnerabilities (KEV) list.CVEDescriptionPatchedTenable BlogCVE-2024-55591Fortinet Authentication Bypass in FortiOS and FortiProxyJanuary 2025CVE-2024-55591: Fortinet Authentication Bypass Zero-Day Vulnerability Exploited in the WildCVE-2024-21762Fortinet FortiOS Out-of-bound Write Vulnerability...

Potential proof of concepts

These PoCs are unverified and could contain malware. Use at your own risk.

delsploit/CVE-2023-27997

github · Created 2023-10-12 17:50:38 UTC · 9 stars

imbas007/CVE-2023-27997-Check

github · Created 2023-06-22 14:16:44 UTC · 1 stars

BishopFox/CVE-2023-27997-check

github · Created 2023-06-16 20:15:36 UTC · 133 stars

Safely detect whether a FortiGate SSL VPN instance is vulnerable to CVE-2023-27997 based on response timing

rio128128/CVE-2023-27997-POC

github · Created 2023-06-16 03:25:19 UTC · 27 stars

POC FortiOS SSL-VPN buffer overflow vulnerability

Timeline

  • CVE ID Reserved

  • Exploit Used in Malware

  • Added to KEVIntel

  • CVE Published to Public

  • Detected by Nessus