# CVE-2021-33044: Dahua IPC/VTH/VTO - Authentication Bypass

> Live exploitation tracking for CVE-2021-33044 by the CrowdSec Live Exploit Tracker, built from real-world attack data crowdsourced from CrowdSec's global network.

Page: https://tracker.crowdsec.net/cves/CVE-2021-33044

## Key facts

- **Exploitation phase:** Limited Exploitation. The vulnerability is known but shows very limited attacker interest or exploitation activity.
- **CVSS score:** 9.8
- **Public exploit available:** Yes
- **Affected products:** Dahua Ipc-hum7xxx, Dahua Ipc-hx3xxx, Dahua Ipc-hx5xxx, Dahua Sd1a1, Dahua Sd22, Dahua Sd41, Dahua Sd50, Dahua Sd52c, Dahua Sd6al, Dahua Tpc-bf1241, Dahua Tpc-bf2221, Dahua Tpc-bf5x01, Dahua Tpc-pt8x21b, Dahua Tpc-sd2221, Dahua Tpc-sd8x21, Dahua Vto-65xxx, Dahua Vto-75x95x, Dahua Vth-542xh, Dahua Tpc-bf5x21
- **Weaknesses:** CWE-287 (Improper Authentication)
- **Tags:** iot

## Description

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.

## CrowdSec analysis

[CVE-2021-33044](https://euvd.enisa.europa.eu/vulnerability/CVE-2021-33044) is an authentication bypass vulnerability present in certain Dahua products, which allows attackers to circumvent device login protections by sending crafted requests.

CrowdSec has been tracking this vulnerability and its exploits since 4th of September 2024.

Insights from the CrowdSec network reveal that the attackers trying to exploit CVE-2021-33044 are composed of a fairly even mix of opportunistic and targeted actors. Some attackers employ preliminary reconnaissance, while others use indiscriminate scanning.
Data from the CrowdSec community also indicates a gradual decrease in attacks targeting CVE-2021-33044. While still present in the wild, exploitation levels have dropped noticeably week-over-week. This may signal that the vulnerability is becoming less relevant or that defenses are improving fast enough for attackers to lose interest.

Attack attempts generally involve requests to URLs containing `/rpc2_login`.

## Timeline

- 2021-09-15: CVE Published. CVE-2021-33044 is published to NVD.
- 2024-08-21: CISA KEV. CVE-2021-33044 is added to the Known Exploited Vulnerabilities catalog by CISA.
- 2024-09-04: Rule Released. CrowdSec releases a rule to detect CVE-2021-33044 exploitation attempts against the CrowdSec Network.
- 2024-09-11: CISA Remediation Deadline. Expiration of the CISA remediation deadline as described in [BOD 22-01](https://www.cisa.gov/news-events/directives/bod-22-01-reducing-significant-risk-known-exploited-vulnerabilities).
- 2024-11-23: CrowdSec First Seen. CrowdSec observes in-the-wild exploitation of CVE-2021-33044 for the first time.

## References

- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-33044.yaml

## Live exploitation data

The [Live Exploit Tracker page](https://tracker.crowdsec.net/cves/CVE-2021-33044) follows observed exploitation activity for CVE-2021-33044. [Request an API key](https://tracker.crowdsec.net/request-api-key) for full access to its exploitation timeline, attacking IP addresses and blocklists.