CVE-2023-33305Network attack vector

Service interruption via infinite-loop HTTP processing

Published Jun 13, 2023 · Updated Oct 22, 2024

Denial of service in Fortinet FortiOS, FortiProxy, and FortiWeb allows remote authenticated users to interrupt service via crafted HTTP requests. The products enter an infinite loop while processing a specially crafted HTTP request; Fortinet has not identified the affected request handler. Administrative access is required, and the documented consequence is service interruption without reported data disclosure or modification.

CVSS severity6.5
Medium
EPSS probability0.83%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Fortinet FortiOS, FortiProxy, and FortiWeb allows remote authenticated users to interrupt service via crafted HTTP requests. The products enter an infinite loop while processing a specially crafted HTTP request; Fortinet has not identified the affected request handler. Administrative access is required, and the documented consequence is service interruption without reported data disclosure or modification.

The record

CVE
CVE-2023-33305
Published
Jun 13, 2023
Updated
Oct 22, 2024
Vendor
Fortinet
Product
FortiWeb
Classifications
CWE-835, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 13, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 22, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=6.3.0 <=6.3.23
  2. Affected versionversion=6.4.0 <=6.4.3
  3. Affected versionversion=7.0.0 <=7.0.6
  4. Affected versionversion=7.2.0 <=7.2.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Fortinet · FortiWebversion=6.3.0 <=6.3.23; version=6.4.0 <=6.4.3; version=7.0.0 <=7.0.6; version=7.2.0 <=7.2.1
Fortinet · FortiOSversion=5.0.0 <=5.0.14; version=5.2.0 <=5.2.15; version=5.4.0 <=5.4.13; version=5.6.0 <=5.6.14; version=6.0.0 <=6.0.17; version=6.2.0 <=6.2.15; version=6.4.0 <=6.4.13; version=7.0.0 <=7.0.10; version=7.2.0 <=7.2.4
Fortinet · FortiProxyversion=1.0.0 <=1.0.7; version=1.1.0 <=1.1.6; version=1.2.0 <=1.2.13; version=2.0.0 <=2.0.12; version=7.0.0 <=7.0.9; version=7.2.0 <=7.2.3

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.9FortinetCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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