FortiproxyApplication · Fortinet
CVE-2023-33305
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA 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 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceAn infinite loop vulnerability exists in the HTTP request handling component of FortiOS, FortiProxy, and FortiWeb. Specially crafted HTTP requests trigger a loop with an unreachable exit condition, causing the affected system to hang and become unresponsive, resulting in denial of service.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
FortiproxyApplication
>= 1.0.0, <= 1.0.7>= 1.1.0, <= 1.1.6>= 1.2.0, <= 1.2.13>= 2.0.0, <= 2.0.12>= 7.0.0, <= 7.0.9>= 7.2.0, <= 7.2.3
FortiwebApplication
>= 6.3.0, <= 6.3.23>= 6.4.0, <= 6.4.3>= 7.0.0, <= 7.0.6= 7.2.0= 7.2.1
FortiosOperating system
>= 5.0.0, <= 5.0.14>= 5.2.0, <= 5.2.15>= 5.4.0, <= 5.4.13>= 5.6.0, <= 5.6.14>= 6.0.0, <= 6.0.17>= 6.2.0, <= 6.2.15>= 6.4.0, <= 6.4.13>= 7.0.0, <= 7.0.9>= 7.2.0, <= 7.2.4CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Identify the Fortinet product and versionRun 'get system status' or 'diag -t' in the FortiOS/FortiProxy CLI. For FortiWeb, run 'get system info' or check the web UI dashboard for the firmware version.Affected if The displayed firmware version falls within any of the affected ranges: FortiProxy 1.0.0-1.0.7, 1.1.0-1.1.6, 1.2.0-1.2.13, 2.0.0-2.0.12, 7.0.0-7.0.9, 7.2.0-7.2.3; FortiWeb 6.3.0-6.3.23, 6.4.0-6.4.3, 7.0.0-7.0.6, 7.2.0-7.2.1; FortiOS 5.0.0-5.0.14, 5.2.0-5.2.15, 5.4.0-5.4.13, 5.6.0-5.6.14, 6.0.0-6.0.1
-
Confirm HTTP/HTTPS management access is enabledRun 'show system interface' or 'get system interface' in the CLI and look for port1 or mgmt interfaces with 'set allowaccess http https' or similar. In FortiWeb, check 'show system global' for admin-http-https status.Affected if HTTP (port 80) or HTTPS (port 443) is listed in the allowed access methods, meaning the vulnerable HTTP request handling component is exposed.
-
Check if the device is directly internet-facingReview firewall policies with 'show firewall policy' or check the interface configuration. Verify whether the management interface or HTTP services are exposed to untrusted networks.Affected if The HTTP/HTTPS service is accessible from untrusted networks or the internet, allowing attackers to send the specially crafted HTTP requests.
-
Verify the device is actively processing HTTP trafficRun 'get system performance firewall statistics' or monitor active sessions with 'get firewall session list'. Check if HTTP proxy or web protection profiles are active.Affected if The device is operating as a proxy (FortiProxy), web application firewall (FortiWeb), or has HTTP traffic inspection enabled, meaning it processes incoming HTTP requests that could trigger the infinite loop.
You are affected if your FortiOS, FortiProxy, or FortiWeb version falls within the affected ranges AND HTTP/HTTPS management or proxy services are enabled and reachable.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedApply the vendor-supplied patches/updates for FortiOS, FortiProxy, and FortiWeb as specified in Fortinet security advisories. For systems that cannot be immediately updated, consider implementing rate limiting or web application firewall rules to mitigate malformed HTTP request vectors.
FortiOS: 7.2.5+/7.0.11+ | FortiProxy: 7.2.4+/7.0.10+ | FortiWeb: 7.2.2+/7.0.7+
- 1. Identify the specific Fortinet product (FortiOS, FortiProxy, or FortiWeb) currently deployed
- 2. Determine the exact version number of the installed instance using the system GUI or CLI command 'get system status'
- 3. For FortiOS: Upgrade to version 7.2.5 or later, or 7.0.11 or later
- 4. For FortiProxy: Upgrade to version 7.2.4 or later, or 7.0.10 or later
- 5. For FortiWeb: Upgrade to version 7.2.2 or later, or 7.0.7 or later
- 6. Before upgrading, review the Fortinet release notes for the target version to confirm the CVE fix is included
- 7. Schedule a maintenance window and back up the current configuration
- 8. Perform the upgrade following Fortinet's standard upgrade procedure
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Fortiproxy
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,600.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-33305 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2023-33305 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data