CVE-2016-5306
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 · uneditedSymantec Endpoint Protection Manager (SEPM) 12.1 before RU6 MP5 does not properly implement the HSTS protection mechanism, which makes it easier for remote attackers to obtain sensitive information by sniffing the network for unintended HTTP traffic on port 8445.
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 confidenceSymantec Endpoint Protection Manager (SEPM) 12.1 prior to RU6 MP5 fails to properly implement HSTS (HTTP Strict Transport Security), allowing sensitive HTTP traffic on port 8445 to be intercepted via network sniffing. This enables remote attackers to capture plaintext communications that should be protected by encrypted HTTPS channels.
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<= 12.1.6CVSS 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
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/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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Identify SEPM versionOpen the Symantec Endpoint Protection Manager console, navigate to Help > About, or check the installation directory for version information. Alternatively, check the installer file name or Windows Programs and Features.Affected if The installed version is 12.1 RU6 MP4 or earlier (any version prior to 12.1 RU6 MP5).
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Verify port 8445 configurationCheck the SEPM management server configuration to confirm whether port 8445 is configured to accept HTTP connections. Inspect the server.xml configuration file in the SEPM installation directory (typically in Tomcat or similar web server config).Affected if Port 8445 accepts unencrypted HTTP connections rather than strictly requiring HTTPS.
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Test for HSTS header on port 8445Use a browser or command-line tool (curl with -I flag) to make an HTTPS request to the SEPM server on port 8445 and inspect the response headers for the Strict-Transport-Security header.Affected if The Strict-Transport-Security header is missing from HTTPS responses on port 8445, or the HSTS header is present but improperly configured.
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Capture network traffic on port 8445Use a network packet analyzer (such as Wireshark) to monitor traffic on port 8445 while accessing the SEPM console. Verify whether plaintext HTTP requests are visible.Affected if Plaintext HTTP traffic is observable on port 8445 when accessing the SEPM management interface.
A system is affected if SEPM version is before 12.1 RU6 MP5 and port 8445 accepts HTTP traffic or does not serve a proper HSTS header.
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 SEPM to version 12.1 RU6 MP5 or later to ensure proper HSTS implementation. Additionally, verify that port 8445 only accepts HTTPS connections and that the HSTS header is being correctly served.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-5306 — 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-2016-5306 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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- Version or environment caveats, and links to real fixes
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