What is CVE-2023-27997?
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.
The record classifies CVE-2023-27997 under weakness classes CWE-122, CWE-787. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 15 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 1233 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 9.8 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS (FIRST)
- 85.6% probability of exploitation in the next 30 days, higher than 99.7% of all scored CVEs
- CISA KEV
- Listed since 2023-06-13, federal remediation deadline 2023-07-04 — used in known ransomware campaigns
- Threadlinqs priority
- 10/10 — CISA lists it as used in ransomware, which Threadlinqs scores at the maximum
- Published
- 2023-06-13, last modified 2026-07-31
Is CVE-2023-27997 being exploited?
CISA added CVE-2023-27997 to the Known Exploited Vulnerabilities catalog on 2023-06-13, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2023-07-04 under BOD 22-01. CISA flags the vulnerability as one used in known ransomware campaigns. Weaponised exploit code for CVE-2023-27997 is publicly available. 11 public proof-of-concept repositories are tracked for this identifier. It currently carries a trending score of 53 in the Threadlinqs vulnerability feed.
- BishopFox/CVE-2023-27997-check (github)
- lexfo/xortigate-cve-2023-27997 (github)
- rio128128/CVE-2023-27997-POC (github)
- delsploit/CVE-2023-27997 (github)
- TechinsightsPro/ShodanFortiOS (github)
- imbas007/CVE-2023-27997-Check (github)
- abraxas/Fortigate-SSL-VPN-Exploit-Kit (github)
- puckiestyle/cve-2023-27997 (github)
Affected products and versions
- Fortinet: Fortios, Fortios 6.2.4, Fortios 7.0.5, Fortios 6.2.6, Fortios 6.4.10, Fortiproxy, Fortios 6.2.7, Fortios 6.4.12, Fortios 6.0.10, Fortios 6.4.6, Fortios 6.4.8, Fortios 6.4.2, Fortios 7.0.10, Fortigate 6000, Fortigate 7000
How to fix CVE-2023-27997
The record marks a vendor fix as available for CVE-2023-27997. Vendor advisory: https://fortiguard.com/psirt/FG-IR-23-097. Because CVE-2023-27997 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2023-07-04. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.
Threat activity tracking CVE-2023-27997
8 tracked threats in the Threadlinqs corpus reference CVE-2023-27997, either in the campaign’s CVE list or as an indicator on the campaign record.
- Operation Escaneo: MexicanMafia (PanchoVilla) Intrusion Campaign Against Mexican Government Agencies and Latin American Financial Institutions — HIGH · 2026-10-23
- Cyble H1 2026 Threat Actor Landscape: 261 Tracked Groups, Five Most Active Actors Profiled — HIGH · 2026-07-27
- CISA Adds Two Known Exploited Vulnerabilities to Catalog: Fortinet FortiOS Information Disclosure (CVE-2025-68686) and Arista VeloCloud Orchestrator OS Command Injection (CVE-2026-16812) — CRITICAL · 2026-07-27
- Sen. Wyden Urges Binding Federal Mandate to Purge Internet-Facing Legacy VPNs for Zero-Trust Remote Access — MEDIUM · 2026-07-27
- FortiBleed: Mass Credential Compromise Campaign Against Internet-Exposed Fortinet FortiGate Devices (86,644 Devices, 194 Countries) — CRITICAL · 2026-07-11
- FortiBleed Credential Theft Campaign Linked to INC and Lynx Ransomware Operations — CRITICAL · 2026-07-05
- FortiBleed Credential Theft Campaign: FortigateSniffer Tool Deployed Against 430,000+ FortiGate Firewalls, Linked to INC Ransom and Lynx Ransomware — CRITICAL · 2026-07-01
- Kyber Ransomware: Post-Quantum Hybrid Encryption Operation Targeting Windows & VMware ESXi — CRITICAL · 2026-04-22
Sources
Enriched from CVE.org, FIRST EPSS, CISA KEV, public proof-of-concept repositories. Last verified by Threadlinqs on .