CVE-2021-35031

Medium
6.8
0.05.010.0
Year
2021
Published
Dec 28, 2021
Known Affected Devices
1
CVSS Score
6.8

What is CVE-2021-35031?

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.

CVSS Vector Breakdown

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

Exploitable from an adjacent network (e.g. same LAN, Wi-Fi segment, Bluetooth).

AC
Attack Complexity
Low

No special conditions required. Exploit can be performed reliably and repeatedly.

PR
Privileges Required
High

Administrative or root-level privileges required to exploit.

UI
User Interaction
None

No user interaction required. Exploit runs without any victim action.

S
Scope
Unchanged

Exploiting the vulnerability only affects the vulnerable component itself.

C
Confidentiality Impact
High

Complete loss of confidentiality. All data on the component may be exposed.

I
Integrity Impact
High

Complete loss of integrity. Attacker can modify any file or data on the component.

A
Availability Impact
High

Complete denial of service. The component becomes fully unavailable.

Known Affected Devices

FAQ

How severe is CVE-2021-35031?

CVE-2021-35031 has a CVSS score of 6.8/10, rated as Medium. Review the affected products list and apply vendor patches.

What does the CVSS score mean for CVE-2021-35031?

CVSS (Common Vulnerability Scoring System) rates vulnerability severity from 0.0 to 10.0. CVE-2021-35031 scores 6.8/10 (Medium). Scores 9.0–10.0 are Critical, 7.0–8.9 are High, 4.0–6.9 are Medium, and below 4.0 are Low.

Which devices are affected by CVE-2021-35031?

The list of devices confirmed to be affected by CVE-2021-35031 is shown in the "Affected Devices" section above. Check your firmware version against the vendor security advisory and apply the latest patch.

How do I fix or mitigate CVE-2021-35031?

Apply the latest firmware or software update from the vendor. Check the References section above for official advisories and patch notes. If no patch is available, consider disabling the affected feature or isolating the device from untrusted networks.