CVE-2016-5311
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 Privilege Escalation vulnerability exists in Symantec Norton Antivirus, Norton AntiVirus with Backup, Norton Security, Norton Security with Backup, Norton Internet Security, Norton 360, Endpoint Protection Small Business Edition Cloud, and Endpoint Protection Cloud Client due to a DLL-preloading without path restrictions, which could let a local malicious user obtain system privileges.
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 confidenceA DLL preloading vulnerability in multiple Norton security products allows a local attacker to place a malicious DLL in a location where the application loads DLLs without full path restrictions, enabling privilege escalation to system privileges.
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< 22.8.0.50< 22.8.0.50< 22.7< 22.7< 22.7< 22.7< 22.7< 22.7CVSS 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
- Local
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/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.
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Identify installed Norton or Symantec security productOpen Programs and Features (Windows) or check for Norton/Symantec executables in Program Files directories. Common executable names include NortonSecurity.exe, Norton360.exe, SEPEndpoint.exe, or similar.Affected if Any Norton or Symantec security product from the affected product list is present on the system
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Determine installed product versionRight-click the product executable, select Properties, then view the Details tab for version information. Alternatively, run the product and check About or Help section.Affected if Version is below 22.8.0.50 for Symantec Endpoint Protection/Endpoint Protection Cloud, or below 22.7 for Norton 360, Norton Antivirus, Norton Family, Norton Internet Security, or Norton Security products
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Check for recent security updatesOpen the Norton product, navigate to Help > About or Check for Updates to see if patches have been applied.Affected if Product reports no recent updates or version remains below the patched thresholds listed above
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Verify application directory permissionsCheck if the directory where the Norton/Symantec product is installed is writable by non-admin users. Right-click the install folder, select Properties, then Security.Affected if Users with limited privileges can write files to the application directory, allowing them to place malicious DLLs that the application will load
You are affected if a Norton or Symantec security product from the list is installed with a version below 22.8.0.50 (Endpoint Protection) or 22.7 (other Norton products) AND the application directory is writable by non-administrator users.
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 data22.722.8.0.50
Apply vendor patches from Symantec for all affected Norton and Endpoint Protection products. Until patched, avoid running the affected applications from untrusted directories and monitor for unauthorized DLL loading.
- Consultation1.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-5311 — 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-2016-5311 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
- No weaponised exploit code, or anything meant to cause harm
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