CVE-2023-49262 is a critical flaw, scored 9.8, in the Hongdian H8951-4G-ESP router: authentication can be bypassed by overflowing the authentication cookie value when a user session is active. Builds before 2310271149 are affected. Update to build 2310271149 or later and keep the management interface off untrusted networks.
What's affected
The record says the authentication mechanism can be bypassed by overflowing the value of the authentication cookie field, provided there is an active user session. The NVD vector is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. 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-190, integer overflow or wraparound, and CWE-287, improper authentication. An arithmetic error in handling the cookie value ends up making the comparison succeed when it should fail.
The advisory does not describe more than that, and this post will not either. What matters for defenders is the precondition: an active session must exist. On a router with administrators signing in during the day, that precondition is often met.
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
Does it matter that a session must be active?
It narrows the window but does not remove the risk, since administrators sign in regularly. The record still scores it 9.8, so patch rather than rely on timing.
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.
