Cyber Resilience

CVE-2023-33299

RCE in Fortinet Fortinac 8.5.0 – 8.5.4

Published
23 June 2023
Modified
21 November 2024
Patch / advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.24 98th percentile
Risk Priority 85 floored blend · peak EPSS

Summary

CVE-2023-33299 is a critical-severity Deserialization of Untrusted Data (CWE-502) vulnerability in Fortinet Fortinac. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2023-33299 is a deserialization of untrusted data vulnerability (CWE-502) affecting Fortinet FortiNAC in all versions below 7.2.1, below 9.4.3, below 9.2.8, and all earlier 8.x releases. The flaw resides in the inter-server communication port and permits remote attackers to supply crafted serialized payloads that the application deserializes without validation.

An unauthenticated network attacker can exploit the issue by sending a malicious request to the exposed inter-server port, resulting in arbitrary code execution with full system privileges. The CVSS 3.1 score of 9.8 reflects the absence of required credentials, user interaction, or network-adjacent access.

The vendor advisory FG-IR-23-074 states that FortiNAC 8.x branches will receive no fixes; customers must upgrade to a supported release (7.2.1 or later, 9.2.8 or later, or 9.4.3 or later) to eliminate the exposure. The associated EPSS score has remained flat at its peak value of 0.1091 with no material upward trajectory after disclosure.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A deserialization of untrusted data in Fortinet FortiNAC below 7.2.1, below 9.4.3, below 9.2.8 and all earlier versions of 8.x allows attacker to execute unauthorized code or commands via specifically crafted request on inter-server communication port. Note FortiNAC versions 8.x…

more

will not be fixed.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-33300Same product: Fortinet Fortinac
CVE-2023-22638Same product: Fortinet Fortinac
CVE-2023-26206Same product: Fortinet Fortinac
CVE-2024-31488Same product: Fortinet Fortinac
CVE-2022-39952Same product: Fortinet Fortinac
CVE-2023-22637Same product: Fortinet Fortinac
CVE-2023-26203Same product: Fortinet Fortinac
CVE-2023-22633Same product: Fortinet Fortinac
CVE-2026-39811Same vendor: Fortinet
CVE-2025-25248Same vendor: Fortinet

Affected Assets

fortinet
fortinac
7.2.0, 7.2.1, 8.3.7, 9.4.0, 9.4.1 · 8.5.0 — 8.5.4 · 8.6.0 — 8.6.5 · 8.7.0 — 8.7.6

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-502

Penetration testing supplies malicious serialized objects, detecting unsafe deserialization and supporting corrective actions.

addresses: CWE-502

Evaluation of untrusted data handling (deserialization testing) reveals unsafe processing, which the required remediation process addresses.

addresses: CWE-502

Untrusted serialized data can be deserialized and observed inside the chamber, blocking gadget-chain exploitation outside the sandbox.

addresses: CWE-502

Validates or rejects untrusted serialized data before deserialization occurs.

addresses: CWE-502

Identifies and blocks malicious code introduced through deserialization of untrusted data at system boundaries.

addresses: CWE-502

Integrity verification of serialized information can detect tampering before deserialization occurs.

addresses: CWE-502

Provenance of associated data allows detection of untrusted sources before deserialization or processing occurs.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-02 none match
prevents

PR.PS-02 addresses only post-deployment updates/patching and cannot prevent introduction of unsafe deserialization code, yet it can remediate some instances when the flaw exists in outdated libraries or components.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing includes validation of deserialization routines and the use of untrusted data, reducing the likelihood that unsafe object reconstruction will be deployed.

prevents

Requiring vetted libraries, regular updates and SAST before release reduces the likelihood that deserialization logic will accept and act on attacker-controlled serialized objects.

finds

Regular scanning of third-party libraries and timely patching reduce the likelihood that unsafe deserialization vulnerabilities remain active.

none

Mandatory malware scanning of data received over networks or storage media intercepts malicious serialized payloads before they are deserialized by the target application.

References