How severe is CVE-2023-28769?

CVE-2023-28769 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2023-28769 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (92nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-28769?

CVE-2023-28769 affects Zyxel Dx5401-b0 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-28769?

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

When was CVE-2023-28769 published?

CVE-2023-28769 was published on 2023-04-27 and last updated on 2026-06-17.

CVE-2023-28769

CVE-2023-28769 is a critical-severity vulnerability in Zyxel Dx5401-b0 Firmware with a CVSS 3.x base score of 9.8. 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-120.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 5% (92nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-120
Affected product: Zyxel Dx5401-b0 Firmware
Published: 2023-04-27
Last modified: 2026-06-17

Description

The buffer overflow vulnerability in the library “libclinkc.so” of the web server “zhttpd” in Zyxel DX5401-B0 firmware versions prior to V5.17(ABYO.1)C0 could allow a remote unauthenticated attacker to execute some OS commands or to cause denial-of-service (DoS) conditions on a vulnerable device.

Frequently asked questions

What is CVE-2023-28769?: The buffer overflow vulnerability in the library “libclinkc.so” of the web server “zhttpd” in Zyxel DX5401-B0 firmware versions prior to V5.17(ABYO.1)C0 could allow a remote unauthenticated attacker to execute some OS commands or to cause denial-of-service (DoS) conditions on a vulnerable device.
How severe is CVE-2023-28769?: CVE-2023-28769 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2023-28769 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (92nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-28769?: CVE-2023-28769 affects Zyxel Dx5401-b0 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-28769?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2023-28769 published?: CVE-2023-28769 was published on 2023-04-27 and last updated on 2026-06-17.

References

https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-vulnerabilities

Affected products (1)

cpe:2.3:o:zyxel:dx5401-b0_firmware:*:*:*:*:*:*:*:*

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