CVE-2021-28149
High PUBLISHEDHongdian H8922 3.0.5 devices allow Directory Traversal. The /log_download.cgi log export handler does not validate user input and allows a remote...
Not yet in CISA KEV
Recommended Action
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
At a Glance
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.
- CVE Published
- May 06, 2021
- Exploitation Reported
- May 06, 2021
- CVSS
- 6.5 Medium
- EPSS
- —
Affected Versions
| Vendor | Product | Version | Status |
|---|---|---|---|
| n/a |
n/a
|
n/a |
Affected |
CVE References
- 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...
Recommended Actions
- Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
- Check enrichment artifacts for scanner coverage and available PoCs before rolling remediation validation.
- Use the Pro API to automate enrichment, telemetry, and workflow delivery for VM, SOC, and CTI pipelines.
Known Exploited Vulnerability Sources
Catalogues that list this CVE as a known exploited vulnerability.
Per-source evidence links for KEV attestations are available through the KEVIntel Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| The Shadowserver First | 2021-05-06 15:12 UTC |
Scanner Artifacts
Nuclei and Metasploit references linked to this CVE.
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-28149.yaml | Apr 25, 2025 |
Virtual Patch
Compensating WAF rules to help reduce exposure to this CVE. Rule content and deployable vendor exports are available with KEVIntel Enterprise.
KEVIntel does not currently have a virtual patch for this CVE. When available, KEVIntel virtual patches ship as deployable ModSecurity, Cloudflare, and AWS WAF rules.
Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to KEVIntel Enterprise users via the Pro API.
Learn About Virtual PatchesCVSS Scores
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
AV:N/AC:L/Au:S/C:P/I:N/A:N
Exploitation Status
Exploited in the wild
Recorded 2021-05-06 15:12:30 UTC · The Shadowserver
Proof of concept available
Recorded 2026-06-12 14:20:22 UTC · Nuclei Templates
Weaknesses (CWE)
-
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Scanner Integrations
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-28149.yaml | Apr 25, 2025 |
Potential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
nuclei · Created Unknown
Timeline
Key exploitation, disclosure, scanner coverage, and KEV attestation events for this CVE.
-
14:20 UTC 28 days ago14:20 UTC · 28 days ago
Public PoC available
Public proof-of-concept code published
-
00:00 UTC about 1 year ago00:00 UTC · about 1 year ago
Nuclei template available
Scanner coverage available
-
15:12 UTC about 5 years ago15:12 UTC · about 5 years ago
Added to KEVIntel KEV Feed
High-confidence, third-party attested exploitation
-
15:12 UTC about 5 years ago15:12 UTC · about 5 years ago
CVE published
Vulnerability disclosed publicly
-
00:00 UTC over 5 years ago00:00 UTC · over 5 years ago
CVE ID reserved
Identifier reserved by the CNA
Automate This Intelligence with the Pro API
Confidence scoring, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
Pro API Example
GET /api/v2/pro/kevs/CVE-2021-28149
{
"cve_id": "CVE-2021-28149",
"title": "Hongdian H8922 3.0.5 devices allow Directory Traversal. The /log_download.cgi...",
"affected_vendor": "Hongdian",
"affected_product": "H8922",
"affected_versions": [
{ "vendor": "...", "product": "...", "status": "affected", "display_label": "..." }
],
"confidence": "High",
"cvss_score": 6.5,
"epss_score": null,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "...": "Pro API fields" },
"proof_of_concepts": [ "..." ],
"scanner_integrations": [ "..." ]
}