CVE-2021-35031 Command injection in GS1900 series firmware

What is CVE-2021-35031?

CVE-2021-35031 is a medium-severity command injection vulnerability in Zyxel GS1900 series firmware, published on 28 Dec 2021. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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.

Weakness: CWE-78

Which versions are affected by CVE-2021-35031?

It affects 14 products.

Products include Zyxel Gs1900-10hp Firmware, Zyxel Gs1900-16 Firmware, Zyxel Gs1900-24 Firmware, Zyxel Gs1900-24e Firmware, Zyxel Gs1900-24ep Firmware, Zyxel Gs1900-24hp Firmware and 8 more.

How do I fix CVE-2021-35031?

No fix has been published for CVE-2021-35031 yet. Limit exposure of the affected software until one is available.

Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.

Is CVE-2021-35031 being exploited?

There is no known exploitation of CVE-2021-35031 in the wild and no public exploit code.

Other vulnerabilities in Zyxel GS1900 series firmware

• CVE-2026-7273 Zyxel GS1900 Series Switches Stack-Based Buffer Overflow Exploited High 8.8
• CVE-2019-15800 Command injection in n/a Critical 9.8
• CVE-2015-5988 Hardcoded credentials in n/a Critical 9.8
• CVE-2015-5989 Auth bypass in n/a Critical 9.8
• CVE-2019-15803 Auth bypass in n/a Critical 9.1

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-xghr-m3mr-m6m9.