CVE-2021-35031
A vulnerability in the TFTP client of Zyxel GS1900 series firmware, XGS1210 series firmware, and...
A vulnerability in the TFTP client of Zyxel GS1900 series firmware, XGS1210 series firmware, and XGS1250 series firmware, which could allow an authenticated LAN user to execute arbitrary OS commands via the GUI of the vulnerable device.
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent network
- Complexity
- Low
- Privileges needed
- High
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
A vulnerability in the TFTP client of Zyxel GS1900 series firmware, XGS1210 series firmware, and XGS1250 series firmware, which could allow an authenticated LAN user to execute arbitrary OS commands via the GUI of the vulnerable device.
- Record
CVE-2021-35031- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-78
- Updated
- 2026-11-02
EUVDEUVD-2021-21678
A vulnerability in the TFTP client of Zyxel GS1900 series firmware, XGS1210 series firmware, and XGS1250 series firmware, which could allow an authenticated LAN user to execute arbitrary OS commands via the GUI of the vulnerable device.
- Record
EUVD-2021-21678- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-xghr-m3mr-m6m9 No score
A vulnerability in the TFTP client of Zyxel GS1900 series firmware, XGS1210 series firmware, and...
A vulnerability in the TFTP client of Zyxel GS1900 series firmware, XGS1210 series firmware, and XGS1250 series firmware, which could allow an authenticated LAN user to execute arbitrary OS commands via the GUI of the vulnerable device.
- Record
GHSA-xghr-m3mr-m6m9- Weakness
- CWE-78
- Updated
- 2026-11-02
NVD
A vulnerability in the TFTP client of Zyxel GS1900 series firmware, XGS1210 series firmware, and XGS1250 series firmware, which could allow an authenticated LAN user to execute arbitrary OS commands via the GUI of the vulnerable device.
- Record
CVE-2021-35031- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H - CVSS 3.1
- 8.0 High
CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.7 High
AV:A/AC:L/Au:S/C:C/I:C/A:C - Weakness
- CWE-78
- Updated
- 2026-11-02
Affected products
- zyxel gs1900 series firmware
- zyxel xgs1210 series firmware
- zyxel xgs1250 series firmware
- zyxel gs1900-10hp firmware
- zyxel gs1900-16 firmware
- zyxel gs1900-24 firmware
- zyxel gs1900-24e firmware
- zyxel gs1900-24ep firmware
- zyxel gs1900-24hp firmware
- zyxel gs1900-24hpv2 firmware
- zyxel gs1900-48 firmware
- zyxel gs1900-48hp firmware
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-35031 is a medium vulnerability (CVSS 6.8) in Zyxel Gs1900 Series Firmware, published December 28, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.48%, the 41st percentile. No source names a fixed version.