CVE intelligence and bounded remediation

CVE-2019-15800 — An issue was discovered on Zyxel GS1900 devices with firmware before 2.50(AAHH.0)C0

Critical CVSS 9.8

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.)

Severity
Critical
CVSS
9.8 (3.1)
Published
2019-11-14
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-78

Affected products

  • zyxel / gs1900-8_firmware
  • zyxel / gs1900-8hp_firmware
  • zyxel / gs1900-10hp_firmware
  • zyxel / gs1900-16_firmware
  • zyxel / gs1900-24e_firmware
  • zyxel / gs1900-24_firmware

Showing 6 representative product identities from 9 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Command, code, expression, and template injection

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace untrusted values to process execution, interpreters, evaluators, template engines, dynamic imports, and administrative scripting features.
  • Determine whether the affected path is reachable across each trust boundary and which service account or host privilege it inherits.
  • Review configuration for optional execution features, unsafe compatibility modes, and shell invocation.

Remediate safely

  • Replace string-built commands or evaluated code with fixed operations and structured argument APIs that do not invoke a shell.
  • Use strict allowlists for operation identifiers and reject unexpected input before it reaches any interpreter.
  • Update the affected component and add inert regression tests covering metacharacters, encoding variants, and alternate request paths.

Authoritative sources

Complete CVE record and remediation plan

The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.