CVE-2023-38320: 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...

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.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.96%

56.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-476

Affected Software

Vendor	Product	Versions
Opennds	Captive Portal	< 10.1.2

References

Timeline

Published: Nov 17, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-38320?

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.

How severe is CVE-2023-38320?

CVE-2023-38320 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.96% probability of exploitation in the next 30 days.

How do I fix CVE-2023-38320?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.