CVE-2023-49259 is a high severity flaw, scored 7.5, in the Hongdian H8951-4G-ESP router: authentication cookies are built from guessable inputs and can be guessed in reasonable time. Builds before 2310271149 are affected. Update to build 2310271149 or later and restrict the management interface to trusted networks.
What's affected
The record says authentication cookies are generated by an algorithm based on the username, a hardcoded secret and the device uptime, and can be guessed in a reasonable time. The NVD vector is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. 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
The record lists CWE-341, predictable from observable state, and CWE-327, use of a broken or risky cryptographic algorithm. A session token should come from a secure random source. When it is derived from inputs an outsider can narrow down, the token only looks secret.
The hardcoded secret in the recipe is the same on every unit, so it adds no protection once known, and uptime is a number that grows in a predictable way. That leaves a small search space, which is what makes guessing feasible.
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
What makes a session cookie safe?
It should come from a cryptographically secure random generator and be long enough that guessing is impractical. A cookie built from a username, a shared secret and uptime is not random.
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.
