CVE-2020-5139
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 vulnerability in SonicOS SSLVPN service allows a remote unauthenticated attacker to cause Denial of Service (DoS) due to the release of Invalid pointer and leads to a firewall crash. This vulnerability affected SonicOS Gen 5 version 5.9.1.7, 5.9.1.13, Gen 6 version 6.5.4.7, 6.5.1.12, 6.0.5.3, SonicOSv 6.5.4.v and Gen 7 version SonicOS 7.0.0.0.
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 vulnerability in SonicOS SSLVPN service allows remote unauthenticated attackers to cause denial of service by releasing an invalid pointer, which leads to a firewall crash. The issue affects multiple generations and versions of SonicOS firmware.
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<= 5.9.1.13>= 6.0.0.0, <= 6.0.5.3>= 6.5.0.0, <= 6.5.1.11>= 6.5.4.0, <= 6.5.4.7= 7.0.0.0<= 6.5.4.4CVSS 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
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/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 installed SonicOS versionAccess the SonicWall management interface or use the CLI command to display the firmware version (typically via 'show version' or similar). Note the exact version number displayed.Affected if The version falls into any of these ranges: <= 5.9.1.13; >= 6.0.0.0 to <= 6.0.5.3; >= 6.5.0.0 to <= 6.5.1.11; >= 6.5.4.0 to <= 6.5.4.7; = 7.0.0.0 (for SonicOS) or <= 6.5.4.4 (for SonicOSv)
-
Confirm the SonicOS variantDetermine whether the device runs SonicOS or SonicOSv by checking the product model and firmware type in the management interface.Affected if The device runs SonicOSv with version <= 6.5.4.4 and matches the vulnerability conditions
-
Verify SSLVPN service is enabledIn the SonicWall management interface, navigate to the SSLVPN settings or use CLI commands to check if the SSLVPN service is currently enabled on the device.Affected if SSLVPN is enabled and the version is within the affected ranges listed above
-
Check SSLVPN network exposureReview the firewall access rules and NAT policies to determine if SSLVPN (typically port 443 or 4443) is accessible from untrusted external networks or the internet.Affected if SSLVPN is enabled and exposed to untrusted networks or the internet
A user is affected if their SonicOS/SonicOSv version falls within the affected version ranges AND the SSLVPN service is enabled and accessible from untrusted networks.
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 dataApply vendor-supplied firmware patches for affected SonicOS versions. As a temporary workaround, consider restricting SSLVPN service exposure to only necessary networks or implementing rate limiting.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 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 $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-5139 — 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-2020-5139 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