CVE intelligence and bounded remediation
CVE-2021-28149 — 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.
- Severity
- Medium
- CVSS
- 6.5 (3.1)
- Published
- 2021-05-06
- CISA KEV
- Not currently listed
- Ecosystem
- operating-system
- Weaknesses
- CWE-22
Affected products
- hongdian / h8922_firmware / 3.0.5
Matched remediation archetype
Path traversal, unsafe upload, and file handling
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Trace untrusted filenames, archive entries, URLs, and path segments into read, write, include, extraction, and upload operations.
- Identify filesystem roots, mount permissions, symbolic-link behavior, archive handling, and whether uploaded content is web-accessible or executable.
- Review canonicalization and containment checks across supported operating systems and storage backends.
Remediate safely
- Generate server-side storage identifiers and resolve paths beneath a fixed root using filesystem-aware containment checks.
- Reject absolute, parent-relative, alternate-separator, device, link, and archive entries that escape the intended root.
- Store uploads outside executable or served paths, validate type and size, and use private atomic temporary files.
Authoritative sources
Complete CVE record and remediation plan
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