# CVE-2023-27997: Fortinet FortiOS and FortiProxy SSL-VPN Heap-Based Buffer Overflow Vulnerability

Source: https://junglewise.ai/threats/cve-2023-27997-fortinet-fortios-and-fortiproxy-ssl-vpn-heap-based-buffer  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2023-06-13. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-2023-27997 · Severity: critical · CVSS 9.8 · Exploited in the wild · Published 2023-06-13

A heap-based buffer overflow vulnerability in Fortinet FortiOS and FortiProxy SSL-VPN allows an unauthenticated remote attacker to execute arbitrary code or commands via specifically crafted requests. The vulnerability has been observed being exploited in the wild.

Technologies: [Fortinet FortiADC](https://junglewise.ai/threats/technologies/fortiadc), [Fortinet FortiOS](https://junglewise.ai/threats/technologies/fortios), [Fortinet FortiProxy SSL-VPN](https://junglewise.ai/threats/technologies/fortiproxy-ssl-vpn). Vendors: [Fortinet](https://junglewise.ai/threats/vendors/fortinet).

## Quick answers

**Is CVE-2023-27997 exploited in the wild?** Yes. CVE-2023-27997 is known to be exploited in the wild, first recorded on 13 June 2023. Treat it as urgent.

**How severe is CVE-2023-27997?** Critical severity, with a CVSS score of 9.8, published 13 June 2023.

**Which products and versions are affected?** Fortinet FortiOS 7.2.4 and below, 7.0.11 and below, 6.4.12 and below, 6.0.16 and below; Fortinet FortiProxy 7.2.3 and below, 7.0.9 and below, 2.0.12 and below, 1.2 all versions, 1.1 all versions.

**Is there a fix for CVE-2023-27997?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2023-27997 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2023-27997?** Check whether you run Fortinet FortiADC, Fortinet FortiOS or Fortinet FortiProxy SSL-VPN. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- Fortinet FortiOS 7.2.4 and below, 7.0.11 and below, 6.4.12 and below, 6.0.16 and below
- Fortinet FortiProxy 7.2.3 and below, 7.0.9 and below, 2.0.12 and below, 1.2 all versions, 1.1 all versions

## Timeline

- 2023-06-13: disclosed
- 2023-06-13: kev added: Added to CISA Known Exploited Vulnerabilities Catalog

## Related threats

- [Fortinet FortiOS authentication bypass in HA command execution](https://junglewise.ai/threats/cve-2026-126259-a-missing-authentication-for-critical-function-vulnerability-in)
- [Fortinet FortiOS stack buffer overflow in WAD proxy](https://junglewise.ai/threats/cve-2026-126258-a-stack-based-buffer-overflow-vulnerability-in-fortinet-fortios)
- [Fortinet FortiOS out-of-bounds read in kernel](https://junglewise.ai/threats/cve-2026-126256-a-out-of-bounds-read-vulnerability-in-fortinet-fortios-8-0-0)
- [Fortinet FortiOS path traversal authentication bypass in SSH daemon](https://junglewise.ai/threats/cve-2026-126255-a-path-traversal-filedir-vulnerability-in-fortinet-fortios-8-0-0)
- [Fortinet FortiOS numeric truncation error in BGP daemon](https://junglewise.ai/threats/cve-2026-126254-a-numeric-truncation-error-vulnerability-in-fortinet-fortios-8-0)