FortiosOperating system · Fortinet
CVE-2015-2323
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 · uneditedFortiOS 5.0.x before 5.0.12 and 5.2.x before 5.2.4 supports anonymous, export, RC4, and possibly other weak ciphers when using TLS to connect to FortiGuard servers, which allows man-in-the-middle attackers to spoof TLS content by modifying packets.
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 confidenceFortiOS 5.0.x before 5.0.12 and 5.2.x before 5.2.4 accepts weak TLS ciphers including anonymous, export, and RC4 when establishing connections to FortiGuard servers. This allows man-in-the-middle attackers to decrypt and modify TLS-protected traffic by leveraging the weak cipher implementations.
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
FortiosOperating system
= 5.0.0= 5.0.1= 5.0.2= 5.0.3= 5.0.4= 5.0.5= 5.0.6= 5.0.7= 5.0.8= 5.0.9= 5.0.10= 5.0.11CVSS 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
- Authentication
- None
- Confidentiality
- Partial
- Integrity
- Partial
- Availability
- None
AV:N/AC:L/Au:N/C:P/I:P/A:N
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.
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Check FortiOS versionRun `get system status` or `fwmtoken` via CLI, or view the system information page in the web UIAffected if Version is 5.0.0 through 5.0.11, or 5.2.0 through 5.2.3 (any version below 5.0.12 in the 5.0.x branch or below 5.2.4 in the 5.2.x branch)
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Verify FortiGuard services are enabledRun `get system fortiguard` or `diagnose debug rating` via CLI to check FortiGuard antivirus and web filtering service statusAffected if FortiGuard services are active and the device is connecting to FortiGuard servers using TLS
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Inspect TLS cipher configuration for FortiGuardRun `get system interface` or check SSL/TLS settings in the web UI under System > Feature Visibility > SSL Inspection, or examine the SSL/SSH profile configuration used for FortiGuard trafficAffected if Weak ciphers (anonymous DH, export-grade ciphers, or RC4) are listed as allowed or no cipher restriction is configured
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Review SSL inspection logs for cipher detailsRun `diagnose ips socket list` or check FortiView > SSL Inspection logs to identify which ciphers are being negotiated with FortiGuard serversAffected if Log entries show connections using NULL cipher, ADH, or export-level ciphers rather than strong cipher suites
If the FortiOS version is 5.0.x below 5.0.12 or 5.2.x below 5.2.4 AND FortiGuard TLS connections are active, the environment is vulnerable to man-in-the-middle attacks via weak TLS ciphers.
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.
From vendor dataUpgrade FortiOS to version 5.0.12 or later (for 5.0.x branches) or 5.2.4 or later (for 5.2.x branches) to eliminate support for weak TLS ciphers in FortiGuard connections.
Fix this in Fortios
Scoped from the published advisory
- Consultation1.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,664.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2015-2323 — 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-2015-2323 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
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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