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TI-2019-11872 Aliases CVE-2019-15803GHSA-958f-78j2-fqr6

An issue was discovered on Zyxel GS1900 devices with firmware before 2.50(AAHH.0)C0.

Priority MEDIUM 42CWE-287Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
High · High · None
Fix status
No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-287.

Summary

An issue was discovered on Zyxel GS1900 devices with firmware before 2.50(AAHH.0)C0. Through an undocumented sequence of keypresses, undocumented functionality is triggered. A diagnostics shell is triggered via CTRL-ALT-t, which prompts for the password returned by fds_sys_passDebugPasswd_ret(). The firmware contains access control checks that determine if remote users are allowed to access this functionality. The function that performs this check (fds_sys_remoteDebugEnable_ret in libfds.so) always return TRUE with no actual checks performed. The diagnostics menu allows for reading/writing arbitrary registers and various other configuration parameters which are believed to be related to the network interface chips.

Why it matters now

EPSS 0.01323 71st percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 18

CPEVersionsRoleVendor
cpe:2.3:o:zyxel:gs1900-8_firmware:*:*:*:*:*:*:*:*before 2.50\(aahh.0\)c0VulnerableZyxel
cpe:2.3:h:zyxel:gs1900-8:-:*:*:*:*:*:*:*not specified by NVDRunning onZyxel
cpe:2.3:o:zyxel:gs1900-8hp_firmware:*:*:*:*:*:*:*:*before 2.50\(aahi.0\)c0VulnerableZyxel
cpe:2.3:h:zyxel:gs1900-8hp:-:*:*:*:*:*:*:*not specified by NVDRunning onZyxel
cpe:2.3:o:zyxel:gs1900-10hp_firmware:*:*:*:*:*:*:*:*before 2.50\(aazi.0\)c0VulnerableZyxel
cpe:2.3:h:zyxel:gs1900-10hp:-:*:*:*:*:*:*:*not specified by NVDRunning onZyxel
cpe:2.3:o:zyxel:gs1900-16_firmware:*:*:*:*:*:*:*:*before 2.50\(aahj.0\)c0VulnerableZyxel
cpe:2.3:h:zyxel:gs1900-16:-:*:*:*:*:*:*:*not specified by NVDRunning onZyxel
cpe:2.3:o:zyxel:gs1900-24e_firmware:*:*:*:*:*:*:*:*before 2.50\(aahk.0\)c0VulnerableZyxel
cpe:2.3:h:zyxel:gs1900-24e:-:*:*:*:*:*:*:*not specified by NVDRunning onZyxel
  • cpe:2.3:o:zyxel:gs1900-8_firmware:*:*:*:*:*:*:*:* Versions before 2.50\(aahh.0\)c0 Vulnerable ·Zyxel
  • cpe:2.3:h:zyxel:gs1900-8:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
  • cpe:2.3:o:zyxel:gs1900-8hp_firmware:*:*:*:*:*:*:*:* Versions before 2.50\(aahi.0\)c0 Vulnerable ·Zyxel
  • cpe:2.3:h:zyxel:gs1900-8hp:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
  • cpe:2.3:o:zyxel:gs1900-10hp_firmware:*:*:*:*:*:*:*:* Versions before 2.50\(aazi.0\)c0 Vulnerable ·Zyxel
  • cpe:2.3:h:zyxel:gs1900-10hp:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
  • cpe:2.3:o:zyxel:gs1900-16_firmware:*:*:*:*:*:*:*:* Versions before 2.50\(aahj.0\)c0 Vulnerable ·Zyxel
  • cpe:2.3:h:zyxel:gs1900-16:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
  • cpe:2.3:o:zyxel:gs1900-24e_firmware:*:*:*:*:*:*:*:* Versions before 2.50\(aahk.0\)c0 Vulnerable ·Zyxel
  • cpe:2.3:h:zyxel:gs1900-24e:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
Show 8 more CPE
CPEVersionsRoleVendor
cpe:2.3:o:zyxel:gs1900-24_firmware:*:*:*:*:*:*:*:*before 2.50\(aahl.0\)c0VulnerableZyxel
cpe:2.3:h:zyxel:gs1900-24:-:*:*:*:*:*:*:*not specified by NVDRunning onZyxel
cpe:2.3:o:zyxel:gs1900-24hp_firmware:*:*:*:*:*:*:*:*before 2.50\(aahm.0\)c0VulnerableZyxel
cpe:2.3:h:zyxel:gs1900-24hp:-:*:*:*:*:*:*:*not specified by NVDRunning onZyxel
cpe:2.3:o:zyxel:gs1900-48_firmware:*:*:*:*:*:*:*:*before 2.50\(aahn.0\)c0VulnerableZyxel
cpe:2.3:h:zyxel:gs1900-48:-:*:*:*:*:*:*:*not specified by NVDRunning onZyxel
cpe:2.3:o:zyxel:gs1900-48hp_firmware:*:*:*:*:*:*:*:*before 2.50\(aaho.0\)c0VulnerableZyxel
cpe:2.3:h:zyxel:gs1900-48hp:-:*:*:*:*:*:*:*not specified by NVDRunning onZyxel
  • cpe:2.3:o:zyxel:gs1900-24_firmware:*:*:*:*:*:*:*:* Versions before 2.50\(aahl.0\)c0 Vulnerable ·Zyxel
  • cpe:2.3:h:zyxel:gs1900-24:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
  • cpe:2.3:o:zyxel:gs1900-24hp_firmware:*:*:*:*:*:*:*:* Versions before 2.50\(aahm.0\)c0 Vulnerable ·Zyxel
  • cpe:2.3:h:zyxel:gs1900-24hp:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
  • cpe:2.3:o:zyxel:gs1900-48_firmware:*:*:*:*:*:*:*:* Versions before 2.50\(aahn.0\)c0 Vulnerable ·Zyxel
  • cpe:2.3:h:zyxel:gs1900-48:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
  • cpe:2.3:o:zyxel:gs1900-48hp_firmware:*:*:*:*:*:*:*:* Versions before 2.50\(aaho.0\)c0 Vulnerable ·Zyxel
  • cpe:2.3:h:zyxel:gs1900-48hp:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2019-15803
  2. 2026-10-03 Alias added: GHSA-958f-78j2-fqr6

References

Exploit 1

Advisory 1

  • TI-2026-06387 Stack-based buffer overflow in Zyxel GS1900-48HPv2 firmware KEVCVSS 3.1HIGH 8.8
  • TI-2019-11869 An issue was discovered on Zyxel GS1900 devices with firmware before 2.50(AAHH.0)C0. CVSS 3.1CRITICAL 9.8
  • TI-2016-01221 Cisco NX-OS 6.0(2)U6(1) through 6.0(2)U6(5) on Nexus 3000 devices and 6.0(2)A6(1) through… CVSS 3.0CRITICAL 9.8
  • TI-2015-05062 Belkin F9K1102 2 devices with firmware 2.10.17 rely on client-side JavaScript code for… CVSS 3.0CRITICAL 9.8
  • TI-2015-05061 The web management interface on Belkin F9K1102 2 devices with firmware 2.10.17 has a… CVSS 3.0CRITICAL 9.8
  • TI-2019-11868 An issue was discovered on Zyxel GS1900 devices with firmware before 2.50(AAHH.0)C0. CVSS 3.1HIGH 8.8
See all 34 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences