CVE-2023-49256 is a high severity flaw, scored 7.5, in the Hongdian H8951-4G-ESP router: the configuration backup can be downloaded without authorization and its passwords decrypted with a hardcoded key. Builds before 2310271149 are affected. Update to that build or later.
What's affected
The record says the configuration backup can be downloaded without authorization and that the included passwords can be decrypted with a hardcoded static key. The NVD vector is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N, a confidentiality only impact. Hongdian's fix is build 2310271149. CERT Polska's advisory says all builds before 2310271149 are affected, that the vendor removed the vulnerabilities in that build, and that the reporter confirmed the fix.
How to check if you're exposed
The advisory gives the cutoff as a firmware build number, so the job is to read the build off the device. Sign in to the router's management page and look at the system or firmware information screen. The exact menu name can differ, so use the vendor's documentation if you cannot find it. Compare what you see with 2310271149.
If you manage many units, record the build for each one in your asset list. Anything earlier than 2310271149 is in the affected range. There is no package manager command for this, because the software ships as part of the device firmware.
What to do now
- List every Hongdian H8951-4G-ESP router you run and read its firmware build.
- Update any unit earlier than build 2310271149 using the firmware from Hongdian. The CERT Polska advisory lists no workarounds, so the update is the remedy.
- Take the management interface off the public internet and off untrusted networks while you work through the fleet.
- Change credentials and any passwords stored in router configuration backups after the update, since several of these issues involve exposed credentials or secrets.
- Add the model to your inventory so future advisories match it automatically.
Why it matters
Two weaknesses combine here: a hardcoded cryptographic key, CWE-321, and hard-coded credentials, CWE-798. Encryption with a key that ships in every unit protects nothing once the key is known.
The practical consequence is credential reuse. If a backup file has been fetched by someone else, the passwords inside it, such as Wi-Fi, VPN or admin secrets, are exposed even after the router is patched. Treat the update as step one and rotation as step two.
This CVE is one of ten that CERT Polska published together for the same router on 12 January 2024. Patching for one means patching for all of them, which is why the single fixed build matters more than any individual score.
Quick check
Is a patched router enough?
The patch stops new downloads, but any secrets already in a backup that someone fetched stay exposed. Rotate the passwords that the configuration held.
Does the advisory offer a workaround instead of the update?
No. The CERT Polska page lists no workarounds and names the update to build 2310271149 or later as the remedy.
Sources
CERT Polska: Hongdian H8951-4G-ESP, CVE-2023-49253 to CVE-2023-49262
Last reviewed: 19 October 2026.
