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.

Published: 2023-11-17 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-38320 is rated Moderate Risk (54/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.59%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-38320

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-12-05 0.45% 0.59% +0.14%
2 2025-11-21 0.52% 0.45% -0.07%
3 2025-11-18 — 0.52% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-38320

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2023-38320

OS Trackers for CVE-2023-38320

vendor priority summary link
debian not yet assigned CVE-2023-38320 not yet assigned priority: Debian including 1 source packages (opennds), 4 status rows across 4 suites (bookworm, forky, sid, trixie): resolved 3, open 1. https://security-tracker.debian.org/tracker/CVE-2023-38320
ubuntu medium CVE-2023-38320 medium priority: Ubuntu including 1 source packages (opennds), 10 status rows across 10 suites (bionic, focal, jammy, lunar, mantic, noble, oracular, trusty, upstream, xenial): ignored 5, DNE 2, not-affected 2, released 1. https://ubuntu.com/security/CVE-2023-38320

Affected software / configurations for CVE-2023-38320

Vendor Product Version Raw CPE
opennds captive_portal < 10.1.2 cpe:2.3:a:opennds:captive_portal:*:*:*:*:*:*:*:*

References for CVE-2023-38320

cvelogic Threat Intelligence