Is CVE-2021-28149 actively exploited?

Yes. KEV Intelligence tracks CVE-2021-28149 as a known exploited vulnerability. Confidence is high.

What exploitation activity has KEV Intelligence observed?

KEV Intelligence has not yet recorded sensor-observed exploitation attempts for CVE-2021-28149. Our sensors continue to monitor for activity targeting this CVE.

Which versions are affected?

Version-level data is not available; KEV Intelligence tracks Hongdian H8922.

No. CVE-2021-28149 is not currently listed in CISA KEV.

Vulnerability report

Exploited in the wild High confidence Not in CISA KEV

CVE-2021-28149

H8922 Path Traversal

Hongdian / H8922

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Severity: CVSS 6.5 · Medium
Confidence: High
Exploit status: Exploited in the wild
EPSS: 15.9%
First observed: —
Last observed: —

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2021-28149 is a vulnerability affecting Hongdian H8922. Hongdian H8922 3.0.5 devices allow Directory Traversal. The /log_download.cgi log export handler does not validate user input and allows a remote attacker...

Is it exploited?

Yes. KEV Intelligence tracks this CVE as a known exploited vulnerability. Confidence is high.

Who is affected?

Hongdian / H8922.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

Hongdian H8922 3.0.5 devices allow Directory Traversal

Hongdian H8922 3.0.5 devices allow Directory Traversal. The /log_download.cgi log export handler does not validate user input and allows a remote attacker with minimal privileges to download any file from the device by substituting ../ (e.g., ../../etc/passwd) This can be carried out with a web browser by changing the file name accordingly.

Upon visiting log_download.cgi?type=../../etc/passwd and logging in, the web server will allow a download of the contents of the /etc/passwd file.

Published: 06 May 2021
Exploitation Reported: 06 May 2021
Attack vector: Remote
Complexity: Low
Privileges: Low
User interaction: None

CVE References

CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2021-28149
en.hongdian.com/Products/Details/H8922 en.hongdian.com · CVE Record http://en.hongdian.com/Products/Details/H8922
ssd-disclosure.com/ssd-advisory-hongdian-h8922-multiple-vulnera... ssd-disclosure.com · CVE Record https://ssd-disclosure.com/ssd-advisory-hongdian-h8922-multiple-vulne...

Exploitation evidence

Why KEV Intelligence marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

The Shadowserver

Recorded 06 May 2021

Independent exploitation attestation added to the KEV Intelligence record.

Proof of concept available

Nuclei Templates

Recorded 12 Jun 2026

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.

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Source	Added
The Shadowserver First	2021-05-06 15:12 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets: 0
User-Agents: 0

Raw values available in Pro and Enterprise.

Scanner coverage

Nuclei template detected 25 Apr 2025.

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Virtual patch status

No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

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Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner	Reference	Detected
Nuclei	https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-28149.yaml	25 Apr 2025

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

6.5 Medium

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

EPSS

15.9%

Weaknesses

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') CWE-22

All CVSS Scores

CVSS v3.1 6.5 Medium

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

CVSS v2.0 4.0 Medium

AV:N/AC:L/Au:S/C:P/I:N/A:N

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

Hongdian H8922 3.0.5 Devices - Local File Inclusion

nuclei · Created Unknown

Timeline

From disclosure to observed exploitation

12 Jun 2026
Public PoC available

Public proof-of-concept code published
25 Apr 2025
Nuclei template available

Scanner coverage available
06 May 2021
Added to KEV Intelligence KEV Feed

High-confidence, third-party attested exploitation
06 May 2021
CVE published

Vulnerability disclosed publicly
11 Mar 2021
CVE ID reserved

Identifier reserved by the CNA

Pro API

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Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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Evidence confidence and provenance
First-party sensor telemetry
PoC and scanner references
Affected versions and enrichment
Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2021-28149

Free JSON includes basic KEV fields

{
  "cve_id": "CVE-2021-28149",
  "confidence": "High",
  "cvss_score": 6.5,
  "cvss_estimated": false,
  "epss_score": 0.1592,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}

Early warning alerts

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