CVE-2023-38320

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-11-17 · updated 2026-06-17
Weakness: CWE-476

Description

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.

Affected products

openNDS Captive Portal: before 10.1.2 — fixed in 10.1.2

How to fix

Upgrade to a fixed version: openNDS Captive Portal 10.1.2. Check the vendor advisory for mitigations.

References

https://github.com/openNDS/openNDS/releases/tag/v10.1.2
https://github.com/openwrt/routing/commit/0b19771fb2dd81e7c428759610aed583171eed80
https://source.sierrawireless.com/resources/security-bulletins/sierra-wireless-technical-bulletin---swi-psa-2023-006/#sthash.2vJg3d85.dpbs
https://github.com/openNDS/openNDS/releases/tag/v10.1.2
https://github.com/openwrt/routing/commit/0b19771fb2dd81e7c428759610aed583171eed80
https://source.sierrawireless.com/resources/security-bulletins/sierra-wireless-technical-bulletin---swi-psa-2023-006/#sthash.2vJg3d85.dpbs

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