How severe is CVE-2023-38320?

CVE-2023-38320 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2023-38320 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-38320?

CVE-2023-38320 affects Opennds Captive Portal. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-38320?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2023-38320 published?

CVE-2023-38320 was published on 2023-11-17 and last updated on 2026-06-17.

CVE-2023-38320

CVE-2023-38320 is a high-severity vulnerability in Opennds Captive Portal with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-476.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (57th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-476
Affected product: Opennds Captive Portal
Published: 2023-11-17
Last modified: 2026-06-17

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.

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 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2023-38320 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-38320?: CVE-2023-38320 affects Opennds Captive Portal. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-38320?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2023-38320 published?: CVE-2023-38320 was published on 2023-11-17 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:opennds:captive_portal:*:*:*:*:*:*:*:*

More vulnerabilities in Opennds Captive Portal

CVE-2023-38316 — Critical (CVSS 9.8): An issue was discovered in OpenNDS Captive Portal before version 10.1.2. When the custom unescape callback is enabled,…
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CVE-2023-38313 — High (CVSS 7.5): An issue was discovered in OpenNDS Captive Portal before 10.1.2. it has a do_binauth NULL pointer dereference that can…
CVE-2023-38314 — Medium (CVSS 6.5): An issue was discovered in OpenNDS Captive Portal before version 10.1.2. It has a NULL pointer dereference in…
CVE-2023-38324 — Medium (CVSS 5.3): An issue was discovered in OpenNDS before 10.1.2. It allows users to skip the splash page sequence (and directly…

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