CVE-2026-31163

Command Injection via DHCP MTU Parameter in ToToLink A3300R Firmware

Published Apr 23, 2026 CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed
Description
An issue was discovered in ToToLink A3300R firmware v17.0.0cu.557_B20221024 allowing attackers to execute arbitrary commands via the dhcpMtu parameter to /cgi-bin/cstecgi.cgi.

Analysis

AI-generated

Technical impact

An OS command‑injection flaw in the ToToLink A3300R firmware allows an attacker to arbitrarily execute commands by supplying malicious input in the dhcpMtu parameter to the /cgi-bin/cstecgi.cgi endpoint. This vulnerability, identified as CWE‑77, gives an attacker control over system commands, potentially leading to full device compromise. The CVE description does not specify authentication requirements, so it is unclear whether authentication is required for exploitation.

Affected Systems

The flaw affects only the ToToLink A3300R router running firmware version 17.0.0cu.557_B20221024. No other products or versions are listed as impacted.

Risk and Exploitability

The CVSS score of 6.5 reflects moderate severity, while the EPSS score of less than 1% suggests a very low probability of exploitation in the wild. The flaw is not currently listed in the CISA KEV catalog. Based on the endpoint and parameter names, it is inferred that the attack is launched remotely over the network, but the CVE description does not state whether authentication is required.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Upgrade the device to a firmware version that fixes the command injection issue
  • Disable or restrict access to the /cgi-bin/cstecgi.cgi endpoint when possible
  • Apply network segmentation or firewall rules to block unauthorized access to the router’s web interface

Generated by OpenCVE AI on April 28, 2026 at 23:53 UTC.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Title Command Injection via DHCP MTU Parameter in ToToLink A3300R Firmware
Type Values Removed Values Added
First Time appeared Totolink
Totolink a3300r
Totolink a3300r Firmware
CPEs cpe:2.3:h:totolink:a3300r:-:*:*:*:*:*:*:*
cpe:2.3:o:totolink:a3300r_firmware:17.0.0cu.557_b20221024:*:*:*:*:*:*:*
Vendors & Products Totolink
Totolink a3300r
Totolink a3300r Firmware
Type Values Removed Values Added
Weaknesses CWE-77
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description An issue was discovered in ToToLink A3300R firmware v17.0.0cu.557_B20221024 allowing attackers to execute arbitrary commands via the dhcpMtu parameter to /cgi-bin/cstecgi.cgi.
References
Weaknesses
  • CWE-77

    Improper Neutralization of Special Elements used in a Command ('Command Injection')

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Apr 23, 2026, 7:04 PM
Reserved
Mar 9, 2026, 12:00 AM
Status
Analyzed
Published
Apr 23, 2026, 7:17 PM
Modified
Nov 11, 2026, 7:10 PM