CVE-2021-33044
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 · uneditedThe identity authentication bypass vulnerability found in some Dahua products during the login process. Attackers can bypass device identity authentication by constructing malicious data 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 · moderate confidenceThis is an authentication bypass vulnerability in Dahua security products (cameras, NVRs, etc.) where attackers can bypass the login identity verification by sending specially crafted malicious data packets during the authentication process. The vulnerability has a CVSS 9.8 critical rating indicating complete bypass of authentication controls.
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< 2.820.0000000.5.r.210705< 2.800.0000000.29.r.210630< 2.820.0000000.18.r.210705< 2.812.0000007.0.r.210706< 2.812.0000007.0.r.210706< 2.812.0000007.0.r.210706< 2.812.0000007.0.r.210706< 2.812.0000007.0.r.210706CVSS 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.
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Identify Dahua devices on your networkScan your network for devices with Dahua vendor MAC OUI (e.g., 00:18:fe, 00:40:9d) or check device documentation/web interface for Dahua brandingAffected if Any Dahua IPC or SD series camera is present on the network
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Retrieve the firmware version from the deviceAccess the device web interface and navigate to System > Info, or use the ONVIF/Dahua HTTP API to query the firmware version (often at /cgi-bin/global.cgi?action=getSystemInfo)Affected if The firmware version cannot be determined or is below the patched versions listed in the CVE
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Compare your firmware version against affected rangesMatch your device model and firmware version against: Hum7xxx < 2.820.0000000.5.r.210705, Hx3xxx < 2.800.0000000.29.r.210630, Hx5xxx < 2.820.0000000.18.r.210705, SD1a1/SD22/SD49/SD50/SD52c < 2.812.0000007.0.r.210706Affected if Your firmware version falls within the affected ranges or is lower than the patched versions listed
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Check if the device is network-accessible from untrusted networksReview firewall rules and network segmentation to determine if the device management interface is exposed to the internet or untrusted LAN segmentsAffected if The device is reachable from external networks or untrusted VLANs without proper access controls
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Verify if default or weak authentication is in useCheck whether the device uses default credentials, has password encryption enabled, or has remote management ports (HTTP 80, HTTPS 443, RTSP 554) exposedAffected if The device uses default credentials, has no password encryption, or exposes management ports to untrusted networks
You are affected if you have any of the listed Dahua devices running firmware versions lower than the patched releases, especially if the device is network-accessible from outside your trusted network segment.
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.
dbcve · scoped2.800.0000000.29.r.2106302.812.0000007.0.r.2107062.820.0000000.5.r.210705
Apply vendor-supplied patches or firmware updates from Dahua immediately. If patches are unavailable, restrict network access to device management interfaces via firewalls or VPNs and monitor for unauthorized access attempts.
Upgrade to firmware version 2.820.0000000.5.r.210705 or later for Ipc Hum7xxx; 2.800.0000000.29.r.210630 or later for Ipc Hx3xxx; 2.820.0000000.18.r.210705 or later for Ipc Hx5xxx; 2.812.0000007.0.r.210706 or later for Sd1a1, Sd22, Sd49, Sd50, Sd52c
- 1. Identify the specific model number (e.g., Ipc Hum7xxx, Ipc Hx3xxx, Ipc Hx5xxx, Sd1a1, Sd22, Sd49, Sd50, Sd52c) of the affected Dahua device
- 2. Determine the current firmware version installed on the device via the web interface or administrative console
- 3. Download the appropriate firmware update from the official Dahua Security website (www.dahuasecurity.com) or authorized distribution channel
- 4. Review the firmware release notes to confirm the update addresses CVE-2021-33044
- 5. Create a backup of the current device configuration before applying the update
- 6. Upload and apply the new firmware version: Ipc Hum7xxx to version 2.820.0000000.5.r.210705 or later; Ipc Hx3xxx to version 2.800.0000000.29.r.210630 or later; Ipc Hx5xxx to version 2.820.0000000.18.r.210705 or later; Sd1a1, Sd22, Sd49, Sd50, Sd52c to version 2.812.0000007.0.r.210706 or later
- 7. Verify the firmware was applied successfully by checking the device version information
- 8. Confirm normal device operation and functionality after the upgrade
Generated from the published advisory — verify against the referenced sources before acting.
- 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-2021-33044 — 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-2021-33044 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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