CVE-2021-33045
The identity authentication bypass vulnerability found in some Dahua products during the login process. Attackers can bypass device identity authentication by constructing malicious data packets.
do firstApply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Can a WAF block it? No. Authentication bypass is a flaw in the application's logic. The attack requests look like normal traffic, so a WAF has nothing to match on.
Also consider: patch · add auth middleware
Based on the weakness type only; no CVE-specific evidence yet. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.
Is CVE-2021-33045 being exploited?
Yes. CVE-2021-33045 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2021-33045?
CVE-2021-33045 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2021-33045?
Yes. A fix has been recorded for CVE-2021-33045. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2021-33045 affect?
CVE-2021-33045 affects dahuasecurity:ipc-hum7xxx_firmware, dahuasecurity:ipc-hx3xxx_firmware, dahuasecurity:ipc-hx5xxx_firmware, dahuasecurity:nvr-1xxx_firmware, and 14 further products or versions. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
- affectedDahua IP Camera devices IPC-HX3XXX, IPC-HX5XXX, and IPC-HUM7XXX Buildtime before May, 2020, Video Intercom devices VTO75X95X, VTO65XXX, and VTH542XH, NVR devices NVR1XXX, NVR2XXX, NVR5XXX, and NVR6XX, XVR devices XVR4xxx, XVR5xxx, and XVR7xxx Buildtime before December, 2019.
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
public exploits
Unvetted proof-of-concept code on GitHub: 1 GitHub proof of concept · 1 Nuclei template
- Dahua IPC/VTH/VTO - Authentication Bypass · detection template · critical
Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.
cisa ssvc
- exploitation
- active
- automatable
- yes
- technical impact
- total
Assessed by CISA 5 Sept 2024 (SSVC 2.0.3).
timeline
- 15 Sept 2021Published
- 11 Oct 2021First proof-of-concept repository on GitHub (unvetted) · 25 days later
- 21 Aug 2024Added to CISA KEV (exploited in the wild) · 1,045 days (about 3 years) later
- 5 Sept 2024CISA SSVC assessment: exploitation active · 16 days later
- 11 Sept 2024CISA remediation due date (US federal agencies) · 5 days later
- 12 Jan 2026CVE record last updated · 489 days (about 1 year) later
- 2 Nov 2026Analysed by vulneraibility.com · 294 days (about 10 months) later
- Linkdahuasecurity.com /support/cybersecurity/details/957
- Linkseclists.org /fulldisclosure/2021/Oct/13
- Linkpacketstormsecurity.com /files/164423/Dahua-Authentication-Bypass.html
- Linkcisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-33045
sources
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA KEV catalog: exploitation, date added, due date
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- Nuclei templates: detection templates
- PoC-in-GitHub: GitHub repositories that claim a proof of concept
- Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.