Cyber Resilience

CVE-2023-33305

DoS in Fortinet Fortios 5.0.0 – 5.0.14

DoS
Published
13 June 2023
Modified
21 November 2024
Patch / advisory
View advisory
CVSS Score v3.1 4.9
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0083 54th percentile
Risk Priority 41 floored blend · peak EPSS

Summary

CVE-2023-33305 is a medium-severity Infinite Loop (CWE-835) vulnerability in Fortinet Fortios. Its CVSS base score is 4.9 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked in the top 46% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability Data

A loop with unreachable exit condition ('infinite loop') in Fortinet FortiOS version 7.2.0 through 7.2.4, FortiOS version 7.0.0 through 7.0.10, FortiOS 6.4 all versions, FortiOS 6.2 all versions, FortiOS 6.0 all versions, FortiProxy version 7.2.0 through 7.2.3, FortiProxy version 7.0.0…

more

through 7.0.9, FortiProxy 2.0 all versions, FortiProxy 1.2 all versions, FortiProxy 1.1 all versions, FortiProxy 1.0 all versions, FortiWeb version 7.2.0 through 7.2.1, FortiWeb version 7.0.0 through 7.0.6, FortiWeb 6.4 all versions, FortiWeb 6.3 all versions allows attacker to perform a denial of service via specially crafted HTTP requests.

CWE(s)
CWE-835

Related Threats

MITRE ATT&CK Enterprise Techniques

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
attack.mitre.org →
T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
attack.mitre.org →
T1499.003 Application Exhaustion Flood Impact
Adversaries may target resource intensive features of applications to cause a denial of service (DoS), denying availability to those applications.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-22254Same product: Fortinet Fortios
CVE-2023-29180Same product: Fortinet Fortios
CVE-2023-33306Same product: Fortinet Fortios
CVE-2023-33307Same product: Fortinet Fortios
CVE-2023-29179Same product: Fortinet Fortios
CVE-2023-26207Same product: Fortinet Fortios
CVE-2024-23111Same product: Fortinet Fortios
CVE-2023-37930Same product: Fortinet Fortios
CVE-2026-59840Same product: Fortinet Fortios
CVE-2025-67862Same product: Fortinet Fortios

Affected Assets

fortinet
fortiproxy
1.0.0 — 1.0.7 · 1.1.0 — 1.1.6 · 1.2.0 — 1.2.13
fortinet
fortiweb
7.2.0, 7.2.1 · 6.3.0 — 6.3.23 · 6.4.0 — 6.4.3 · 7.0.0 — 7.0.6
fortinet
fortios
5.0.0 — 5.0.14 · 5.2.0 — 5.2.15 · 5.4.0 — 5.4.13

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.

CP-7 Alternate Processing Site
addresses: CWE-835

Enables transfer to alternate site if an infinite loop at the primary renders processing unavailable.

SC-5 Denial-of-service Protection
addresses: CWE-835

Detects and mitigates infinite loops that produce sustained resource consumption.

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-06 mostly match
prevents

Secure SDLC practices (reviews, testing, static analysis) directly prevent introduction of infinite-loop defects.

ID.RA-01 partial match
prevents

Static analysis and vuln scanning during asset assessment can detect unreachable loop exits.

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.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing can uncover infinite-loop conditions before release.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates practices that can detect and prevent infinite-loop defects.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify loop-termination rules, indirectly reducing the weakness.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly address loop termination and prevent infinite loops.

A.8.27 Secure system architecture and engineering principles none match
none

Secure architecture principles encourage designs that avoid unreachable exit conditions.

A.8.32 Change management none match
none

Change management can require review of loop logic when code is modified.

References