CVE-2019-15800

Name: CVE-2019-15800
Creator: NVD / NIST
Published: 2019-11-14T21:15:11.687+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 3.87%

Last modified Jun 17, 2026

CVE-2019-15800 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. An issue was discovered on Zyxel GS1900 devices with firmware before 2.50(AAHH.0)C0. Due to lack of input validation in the cmd_sys_traceroute_exec(), cmd_sys_arp_clear(), and cmd_sys_ping_exec() functions in the libclicmd.so library contained in the firmware, an attacker could leverage these functions to call system() and execute arbitrary commands on the switches. EPSS estimates a 3.87% chance of exploitation in the next 30 days.

Description

An issue was discovered on Zyxel GS1900 devices with firmware before 2.50(AAHH.0)C0. Due to lack of input validation in the cmd_sys_traceroute_exec(), cmd_sys_arp_clear(), and cmd_sys_ping_exec() functions in the libclicmd.so library contained in the firmware, an attacker could leverage these functions to call system() and execute arbitrary commands on the switches. (Note that these functions are currently not called in this version of the firmware, however an attacker could use other vulnerabilities to finally use these vulnerabilities to gain code execution.)

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

3.87%

88.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-78

Affected Software

Vendor	Product	Versions
Zyxel	Gs1900-8 Firmware	< 2.50\(aahh.0\)c0
Zyxel	Gs1900-8hp Firmware	< 2.50\(aahi.0\)c0
Zyxel	Gs1900-10hp Firmware	< 2.50\(aazi.0\)c0
Zyxel	Gs1900-16 Firmware	< 2.50\(aahj.0\)c0
Zyxel	Gs1900-24e Firmware	< 2.50\(aahk.0\)c0
Zyxel	Gs1900-24 Firmware	< 2.50\(aahl.0\)c0
Zyxel	Gs1900-24hp Firmware	< 2.50\(aahm.0\)c0
Zyxel	Gs1900-48 Firmware	< 2.50\(aahn.0\)c0
Zyxel	Gs1900-48hp Firmware	< 2.50\(aaho.0\)c0

References

https://jasper.la/exploring-zyxel-gs1900-firmware-with-ghidra.htmlExploit, Third Party Advisory
https://www.zyxel.com/support/gs1900-switch-vulnerabilities.shtmlVendor Advisory
https://jasper.la/exploring-zyxel-gs1900-firmware-with-ghidra.htmlExploit, Third Party Advisory
https://www.zyxel.com/support/gs1900-switch-vulnerabilities.shtmlVendor Advisory

Timeline

Published: Nov 14, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-15800?

How severe is CVE-2019-15800?

CVE-2019-15800 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 3.87% probability of exploitation in the next 30 days.

How do I fix CVE-2019-15800?

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.

Are you affected by CVE-2019-15800?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST