CVE-2021-33045 — Dahua IP Camera Authentication Bypass Vulnerability
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.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Confirmed exploitation (CISA KEV)+35
- Public exploit/PoC (nuclei, github)+10
- EPSS 99.6% (30-day exploitation probability)+15
- Technical severity (critical)+10
- Automatable exploitation (SSVC)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
CISA required action CISA
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
US federal deadline: Sep 11, 2024 — passed 764 day(s) ago
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Dahuasecurity Ipc-hum7xxx Firmware, Dahuasecurity Ipc-hx3xxx Firmware, Dahuasecurity Ipc-hx5xxx Firmware…).
- Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- EPSS ahead of 100% of scored CVEs: prioritize it in the patch queue.
- Search available logs for exploit probes matching the vulnerability class (authentication), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Dahuasecurity | Ipc-hum7xxx Firmware | < 2.820.0000000.5.r.210705 | Vulnerable | NIST National Vulnerability Database |
| Dahuasecurity | Ipc-hx3xxx Firmware | < 2.800.0000000.29.r.210630 | Vulnerable | NIST National Vulnerability Database |
| Dahuasecurity | Ipc-hx5xxx Firmware | < 2.820.0000000.5.r.210705 | Vulnerable | NIST National Vulnerability Database |
| Dahuasecurity | Nvr-1xxx Firmware | < 4.001.0000005.1.r.210709 | Vulnerable | NIST National Vulnerability Database |
| Dahuasecurity | Nvr-2xxx Firmware | < 4.001.0000000.1.r.210710 | Vulnerable | NIST National Vulnerability Database |
| Dahuasecurity | Nvr-4xxx Firmware | < 4.001.0000005.1.r.210713 | Vulnerable | NIST National Vulnerability Database |
| Dahuasecurity | Nvr-5xxx Firmware | < 4.001.0000000.0.r.210710 | Vulnerable | NIST National Vulnerability Database |
| Dahuasecurity | Nvr-6xx Firmware | < 4.001.0000001.1.r.210716 | Vulnerable | NIST National Vulnerability Database |
| Dahuasecurity | Vth-542xh Firmware | < 4.500.0000002.0.r.210715 | Vulnerable | NIST National Vulnerability Database |
| Dahuasecurity | Vto-65xxx Firmware | < 4.300.0000004.0.r.210715 | Vulnerable | NIST National Vulnerability Database |
| Dahuasecurity | Vto-75x95x Firmware | < 4.300.0000003.0.r.210714 | Vulnerable | NIST National Vulnerability Database |
| Dahuasecurity | Xvr-4x04 Firmware | versions not specified by the source< 4.001.0000001.1.r.210709 | Vulnerable | NIST National Vulnerability Database |
| Dahuasecurity | Xvr-4x08 Firmware | < 4.001.0000001.1.r.210709 | Vulnerable | NIST National Vulnerability Database |
| Dahuasecurity | Xvr-5x04 Firmware | < 4.001.0000003.1.r.210710 | Vulnerable | NIST National Vulnerability Database |
| Dahuasecurity | Xvr-5x08 Firmware | < 4.001.0000003.1.r.210710 | Vulnerable | NIST National Vulnerability Database |
| Dahuasecurity | Xvr-5x16 Firmware | < 4.001.0000003.1.r.210710 | Vulnerable | NIST National Vulnerability Database |
| Dahuasecurity | Xvr-7x16 Firmware | < 4.001.0000003.1.r.210710 | Vulnerable | NIST National Vulnerability Database |
| Dahuasecurity | Xvr-7x32 Firmware | < 4.001.0000003.1.r.210710 | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 9.8 | CVSS 3.1 | Critical | 3.9 | 5.9 | nvd@nist.gov via NIST National Vulnerability Database |
| 9.8 | CVSS 3.1 | Critical | 3.9 | 5.9 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database |
| 9.8 | CVSS 3.1 | Critical | — | — | GitHub, Inc. via GitHub Security Advisories |
| 9.8 | CVSS 3.1 | Critical | — | — | CISA-ADP via CVE Program (cve.org) e CISA ADP |
| 10.0 | CVSS 2.0 | High | 10.0 | 10.0 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
CISA KEV details CISA
CISA lists a CVE once it has evidence of exploitation against real targets.
CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.
Public exploits, PoCs and detection templates
Public code that demonstrates or tests the flaw raises the odds of mass exploitation — and Nuclei templates help find vulnerable assets in your environment.
- dongpohezui/cve-2021-33045 ★ 9 Oct 11, 2021
Warning: public PoCs are sometimes disguised malware. Use them only for authorized testing in an isolated environment. This portal does not host exploit code — it only points to the sources.
EPSS over time FIRST
Oct 12, 2026 → Oct 14, 2026 · 3 reading(s) · max 99.59%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Review authentication logs: logins without MFA, anomalous sessions and recently created accounts.
- Hunt retroactively in logs from before Aug 21, 2024 (KEV listing): exploitation may have started earlier.
Timeline
What happened to this CVE, newest first.
- 2026
- SSVC assessment updated
- Record published
- Affected products added · dahuasecurity/ipc-hum7xxx firmware, dahuasecurity/ipc-hx3xxx firmware, dahuasecurity/ipc-hx5xxx firmware, dahuasecurity/
- CVSS changed · 9.8
- Source status changed · → Analyzed
- Added to CISA KEV (detected)
- Record created in this database
- 2024
- Added to CISA KEV catalog
- 2021
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 13, 2026 – Oct 13, 2026
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
6 on the record
- www.dahuasecurity.com/support/cybersecurity/details/957
- www.cisa.gov/known-exploited-vulnerabilities-catalog
- seclists.org/fulldisclosure/2021/Oct/13
- nvd.nist.gov/vuln/detail/CVE-2021-33045
- github.com/advisories/GHSA-9vwj-hj2h-whjq
- packetstormsecurity.com/files/164423/Dahua-Authentication-Bypass.html
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2021-33044 Dahua IP Camera Authentication Bypass Vulnerability KEV Sep 15, 2021
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2021-33045 is "Dahua IP Camera Authentication Bypass Vulnerability", rated Critical. It affects Ipc-hum7xxx Firmware (Dahuasecurity); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 9.8 describes technical severity. EPSS 99.59% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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