# CVE-2024-55599: Fortinet FortiOS and FortiProxy DNS filter bypass via Apple devices

Source: https://junglewise.ai/threats/cve-2024-55599-fortinet-fortios-and-fortiproxy-dns-filter-bypass-via-apple  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2025-07-08. Updated: 2026-06-09  
License: CC BY 4.0 with a link back

CVE-2024-55599 · Severity: medium · CVSS 5.3 · Published 2025-07-08

A security flaw in Fortinet's networking software allows users on Apple devices to bypass DNS filtering protections. This means that restricted or malicious websites that should be blocked by the corporate firewall may remain accessible to these devices. While it does not directly lead to data theft, it undermines the security policies intended to protect the network from harmful content.

Technologies: [Fortinet FortiOS](https://junglewise.ai/threats/technologies/fortios), [Fortinet FortiProxy](https://junglewise.ai/threats/technologies/fortiproxy), [Fortinet Fortisase](https://junglewise.ai/threats/technologies/fortisase). Vendors: [Fortinet](https://junglewise.ai/threats/vendors/fortinet).

## Quick answers

**Is CVE-2024-55599 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2024-55599 being exploited in the wild.

**How severe is CVE-2024-55599?** Medium severity, with a CVSS score of 5.3, published 8 July 2025.

**Which products and versions are affected?** Fortinet FortiOS 7.6.0, 7.4.0 through 7.4.7, 7.2.0 through 7.2.10, 7.0 all versions, 6.4 all versions; Fortinet FortiProxy 7.6.0 through 7.6.1, 7.4.0 through 7.4.8, 7.2 all versions, 7.0 all versions; Fortinet Fortisase 24.4.a.

**Is there a fix for CVE-2024-55599?** 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-2024-55599 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2024-55599?** Check whether you run Fortinet FortiOS, Fortinet FortiProxy or Fortinet Fortisase at an affected version. 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.

## Technical details

The vulnerability (CWE-358) exists in the DNS filtering component of FortiOS and FortiProxy. It is triggered by DNS type 65 (HTTPS) resource record requests, which are commonly used by Apple devices for encrypted client hello and HTTP/3 discovery. Because these specific record types are not correctly handled by the security check, an unauthenticated attacker on the network can bypass configured DNS filters to reach restricted domains. The issue affects multiple versions of FortiOS, FortiProxy, and FortiSASE. Patches are available in FortiOS 7.6.1, 7.4.8, and 7.2.11, and FortiProxy 7.6.2 and 7.4.9.

## Affected products

- Fortinet FortiOS 7.6.0, 7.4.0 through 7.4.7, 7.2.0 through 7.2.10, 7.0 all versions, 6.4 all versions
- Fortinet FortiProxy 7.6.0 through 7.6.1, 7.4.0 through 7.4.8, 7.2 all versions, 7.0 all versions
- Fortinet FortiSASE 24.4.a

## Timeline

- 2025-07-08: disclosed: Initial publication by Fortinet
- 2025-07-08: advisory: Fortinet advisory FG-IR-24-053 published

## References

- [https://fortiguard.fortinet.com/psirt/FG-IR-24-053](https://fortiguard.fortinet.com/psirt/FG-IR-24-053)
- [https://cert-portal.siemens.com/productcert/html/ssa-864900.html](https://cert-portal.siemens.com/productcert/html/ssa-864900.html)

## 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)