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CVE-2021-39363

31
FAUCET Score

CVE-2021-39363 is a critical vulnerability affecting Honeywell HDZP252DI and HBW2PER1 devices, allowing for a video replay attack after successful ARP cache poisoning. With a CVSS score of 9.8, this vulnerability is easily exploitable over the network with low complexity, enabling an unauthenticated attacker to achieve high impact on confidentiality, integrity, and availability. While there is no evidence of active exploitation or publicly available exploit code in Metasploit, Nuclei, or ExploitDB, the vulnerability has garnered significant community discussion, indicating awareness among security researchers.

Impacted Technologies

VendorProductVersion(s)CPE
1.00.hw02.4CPE matchmatch criteria
cpe:2.3:o:honeywell:hdzp252di_firmware:1.00.hw02.4:*:*:*:*:*:*:*
1.000.hw01.3CPE matchmatch criteria
cpe:2.3:o:honeywell:hbw2per1_firmware:1.000.hw01.3:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

9.8CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
Exploitability Score
3.9
Impact Score
5.9
CvssVersion
3.1

Exploit Intelligence

EPSS Score
1.42%
Probability of exploitation in next 30 days
EPSS Percentile
70.1%
Percentile rank of EPSS score among Peer Group
As of 2026-07-28
Model: v2026.06.15
This CVE's current EPSS score of 0.0142 is in the 57th percentile among its peer group of 36,897 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.3 Bluesky, 0.3 Mastodon, and 2.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (1)

coollabspatch availablevia llm_extracted

Vendor Advisories (1)

coollabsllm-coollabs-d0260b06acb90fdfMEDIUM

Command Injection HDZP252DI

Jan 26, 2022

References

buildings.honeywell.com / content/dam/hbtbt/en/documents/downloads/Security_Notification_SN_2022-01-26-01_CVE-2021-39363_Command_Injection_HDZP252DI.pdf
Vendor Advisory
buildings.honeywell.com / us/en/brands/our-brands/security/support-and-resources/product-resources/eol-and-security-notices
Vendor Advisory
honeywell.com / us/en/product-security
Vendor Advisory