An issue was discovered in OpenNDS Captive Portal before version 10.1.2. It has a show_preauthpage NULL pointer dereference that can be triggered with a crafted GET HTTP with a missing User-Agent header. Triggering this issue results in crashing OpenNDS (a Denial-of-Service condition). This problem was fixed in OpenWrt master, OpenWrt 23.05 and OpenWrt 22.03 on 28. August 2023 by updating OpenNDS to version 10.1.3.
A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Captive_portal | Opennds | * | 10.1.2 (excluding) |
| Opennds | Ubuntu | bionic | * |
| Opennds | Ubuntu | lunar | * |
| Opennds | Ubuntu | mantic | * |
| Opennds | Ubuntu | trusty | * |
| Opennds | Ubuntu | xenial | * |