CVE-2020-3923
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 · uneditedDVR firmware in TAT-76 and TAT-77 series of products, provided by TONNET, contain misconfigured authentication mechanism. Attackers can crack the default password and gain access to the system.
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 · moderate confidenceThe TAT-76 and TAT-77 series DVR firmware from TONNET contains a misconfigured authentication mechanism that allows attackers to crack default credentials and gain unauthorized system access. This is a critical vulnerability due to the ease of exploitation and the high-value nature of video surveillance systems.
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<= tat-77104g1_20190107<= tat-77208g1_20181225<= tat-71416g1_20181225<= tat-71832g1_20190510<= 20181220_76104g3<= 20181221_76208g3<= 20181221_76216g3<= tat-70832g3_20181221-1CVSS 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
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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.
-
Identify Tonnet DVR device modelsLocate the physical DVR hardware or check network inventory for devices with model numbers in the TAT-76 or TAT-77 series, specifically: Tat 77104g1, Tat 70432n, Tat 71416g1, Tat 71832g1, Tat 76104g3, Tat 76108g3, Tat 76116g3, or Tat 76132g3Affected if The environment contains any of these specific Tonnet DVR model numbers
-
Check installed firmware versionAccess the DVR device web interface or use the manufacturer's tool to retrieve the current firmware version. Compare the installed version string against the affected version thresholds: tat-77104g1_20190107, tat-77208g1_20181225, tat-71416g1_20181225, tat-71832g1_20190510, 20181220_76104g3, 20181221_76208g3, 20181221_76216g3, or tat-70832g3_20181221-1Affected if The installed firmware version is equal to or older than the listed version for your specific model
-
Verify default credentials statusAttempt to log into the DVR web interface or telnet/SSH service using the manufacturer's default credentials (typically admin/admin, admin/123456, or root/123456 for these devices)Affected if Default credentials still grant access to the device management interface
-
Check for exposed management interfacesScan network for open ports on the DVR devices, particularly HTTP (80/8080), HTTPS (443), telnet (23), or RTSP (554) ports that are accessible from untrusted networksAffected if Remote management ports are exposed to the internet or untrusted network segments without VPN or firewall filtering
-
Confirm DVR is operational and reachablePing or perform a port scan to verify the DVR device is online and responding on the networkAffected if The device is powered on and connected to the network, making it potentially exploitable if other conditions are met
Your environment is affected if you have any Tonnet TAT-76 or TAT-77 series DVR devices running firmware versions at or below the specified thresholds AND the default credentials remain unchanged or management interfaces are exposed.
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 dataImmediately change all default credentials on affected DVR devices, disable unnecessary remote access interfaces, and apply any available firmware updates from the vendor. Consider network segmentation to limit exposure.
- Consultation6.0 h
- Implementation12.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,448.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-3923 — 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-2020-3923 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