CVE-2021-28149

Exp

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: 2021-05-06 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-28149 is rated High Exploit Risk (76.3/100): CVSS Medium severity, with high exploitation likelihood (EPSS 90.66%, 100th percentile). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2021-28149

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-28149

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-04 90.23% 90.66% +0.42%
2 2026-03-01 90.66% 90.23% -0.42%
3 2026-02-04 — 90.66% —

Full EPSS history (57 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-28149

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 3.6 [email protected]
4.0 2.0 MEDIUM
AV:N/AC:L/Au:S/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 8.0 2.9 [email protected]

Weakness enumeration for CVE-2021-28149

Affected software / configurations for CVE-2021-28149

Vendor Product Version Raw CPE
hongdian h8922_firmware 3.0.5 cpe:2.3:o:hongdian:h8922_firmware:3.0.5:*:*:*:*:*:*:*

References for CVE-2021-28149

cvelogic Threat Intelligence