How severe is CVE-2023-33237?

CVE-2023-33237 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2023-33237 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (40th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-33237?

CVE-2023-33237 affects Moxa Tn-5900 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-33237?

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-2023-33237 published?

CVE-2023-33237 was published on 2023-08-17 and last updated on 2026-06-17.

CVE-2023-33237

CVE-2023-33237 is a high-severity vulnerability in Moxa Tn-5900 Firmware with a CVSS 3.x base score of 8.8. 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-287.

Key facts

Severity: High (CVSS 3.x base score 8.8)
EPSS exploit prediction: 1% (40th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Moxa Tn-5900 Firmware
Published: 2023-08-17
Last modified: 2026-06-17

Description

TN-5900 Series firmware version v3.3 and prior is vulnerable to improper-authentication vulnerability. This vulnerability arises from inadequate authentication measures implemented in the web API handler, allowing low-privileged APIs to execute restricted actions that only high-privileged APIs are allowed This presents a potential risk of unauthorized exploitation by malicious actors.

Frequently asked questions

What is CVE-2023-33237?: TN-5900 Series firmware version v3.3 and prior is vulnerable to improper-authentication vulnerability. This vulnerability arises from inadequate authentication measures implemented in the web API handler, allowing low-privileged APIs to execute restricted actions that only high-privileged APIs are allowed This presents a potential risk of unauthorized exploitation by malicious actors.
How severe is CVE-2023-33237?: CVE-2023-33237 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2023-33237 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (40th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-33237?: CVE-2023-33237 affects Moxa Tn-5900 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-33237?: 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-2023-33237 published?: CVE-2023-33237 was published on 2023-08-17 and last updated on 2026-06-17.

References

https://www.moxa.com/en/support/product-support/security-advisory/mpsa-230402-tn-5900-and-tn-4900-series-web-server-multiple-vulnerabilities

Affected products (1)

cpe:2.3:o:moxa:tn-5900_firmware:*:*:*:*:*:*:*:*

More vulnerabilities in Moxa Tn-5900 Firmware

CVE-2021-46560 — Critical (CVSS 9.8): The firmware on Moxa TN-5900 devices through 3.1 allows command injection that could lead to device damage.
CVE-2023-34213 — High (CVSS 8.8): TN-5900 Series firmware versions v3.3 and prior are vulnerable to command-injection vulnerability. This vulnerability…
CVE-2023-33239 — High (CVSS 8.8): TN-4900 Series firmware versions v1.2.4 and prior and TN-5900 Series firmware versions v3.3 and prior are vulnerable to…
CVE-2023-34217 — High (CVSS 8.1): TN-4900 Series firmware versions v1.2.4 and prior and TN-5900 Series firmware versions v3.3 and prior are vulnerable to…
CVE-2023-34216 — High (CVSS 8.1): TN-4900 Series firmware versions v1.2.4 and prior and TN-5900 Series firmware versions v3.3 and prior are vulnerable to…
CVE-2021-46559 — High (CVSS 7.5): The firmware on Moxa TN-5900 devices through 3.1 has a weak algorithm that allows an attacker to defeat an inspection…

All CVEs affecting Moxa Tn-5900 Firmware →

Other CWE-287 (Improper Authentication) vulnerabilities

CVE-2026-45480 — Critical (CVSS 10.0): Improper authentication in Azure Active Directory allows an unauthorized attacker to elevate privileges over a network.
CVE-2026-46389 — Critical (CVSS 10.0): UDS Identity Config builds the Keycloak configuration image (realm, plugins, theme, truststore, JARs) consumed by UDS…
CVE-2026-10611 — Critical (CVSS 10.0): An authentication bypass vulnerability exists in MISP when LDAP mixed authentication is enabled with OTP enforcement.…
CVE-2026-47280 — Critical (CVSS 10.0): Improper authentication in Azure Resource Manager (ARM) allows an unauthorized attacker to elevate privileges over a…
CVE-2026-42822 — Critical (CVSS 10.0): Improper authentication in Azure Local Disconnected Operations allows an unauthorized attacker to elevate privileges…
CVE-2026-20182 — Critical (CVSS 10.0): May 2026: This security advisory provides the details and fix information for a vulnerability that was discovered and…

Browse all CWE-287 (Improper Authentication) vulnerabilities →