Description
A security vulnerability has been detected in Totolink A7100RU 7.4cu.2313_b20191024. Impacted is the function setDdnsCfg of the file /cgi-bin/cstecgi.cgi. Such manipulation of the argument provider leads to os command injection. The attack may be launched remotely. The exploit has been disclosed publicly and may be used.
Published: 2026-04-06
Score: 6.9 Medium
EPSS: 4.7% Low
KEV: No
Impact: Remote Code Execution
Action: Immediate Patch
AI Analysis

Impact

The A7100RU firmware contains a flaw in the setDdnsCfg function of /cgi-bin/cstecgi.cgi. An attacker can supply crafted URL parameters that are passed to the underlying shell without proper sanitization, allowing them to execute arbitrary OS commands on the device. This vulnerability is a classic example of OS command injection (CWE‑77, CWE‑78) and can lead to remote code execution, compromising confidentiality, integrity, and availability of the device’s network traffic.

Affected Systems

Only the Totolink A7100RU routers running firmware 7.4cu.2313_b20191024 are affected. The flaw resides in the cstecgi.cgi script bundled with that firmware release. No other Totolink products or firmware versions are reported to be impacted by this defect.

Risk and Exploitability

With a CVSS base score of 6.9, the risk is moderate but the flaw allows full remote code execution. The EPSS score is not available, but the vulnerability has been publicly disclosed and demonstrated, indicating that exploitation is feasible without special conditions. Because the attack vector is remote, any user connecting to the web interface from an untrusted network is potentially exposed; the vendor has not listed it in the KEV catalog, but the public availability of exploit code raises concern.

Generated by OpenCVE AI on April 7, 2026 at 01:53 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Check the current firmware version of your Totolink A7100RU router.
  • Download the latest firmware from Totolink’s official website or support portal.
  • Apply the firmware update following Totolink’s instructions and reboot the device.
  • Verify that the cstecgi.cgi setDdnsCfg endpoint is no longer vulnerable by performing a harmless command injection test or using a vendor‑provided test tool.
  • If an update cannot be applied immediately, restrict remote access to the device’s web interface (e.g., via ACLs or firewall rules) and monitor for anomalous traffic.

Generated by OpenCVE AI on April 7, 2026 at 01:53 UTC.

Tracking

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Advisories

No advisories yet.

History

Wed, 08 Apr 2026 14:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

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

Tue, 07 Apr 2026 09:45:00 +0000

Type Values Removed Values Added
First Time appeared Totolink a7100ru
Vendors & Products Totolink a7100ru

Tue, 07 Apr 2026 00:00:00 +0000

Type Values Removed Values Added
Description A security vulnerability has been detected in Totolink A7100RU 7.4cu.2313_b20191024. Impacted is the function setDdnsCfg of the file /cgi-bin/cstecgi.cgi. Such manipulation of the argument provider leads to os command injection. The attack may be launched remotely. The exploit has been disclosed publicly and may be used.
Title Totolink A7100RU cstecgi.cgi setDdnsCfg os command injection
First Time appeared Totolink
Totolink a7100ru Firmware
Weaknesses CWE-77
CWE-78
CPEs cpe:2.3:o:totolink:a7100ru_firmware:*:*:*:*:*:*:*:*
Vendors & Products Totolink
Totolink a7100ru Firmware
References
Metrics cvssV2_0

{'score': 7.5, 'vector': 'AV:N/AC:L/Au:N/C:P/I:P/A:P/E:POC/RL:ND/RC:UR'}

cvssV3_0

{'score': 7.3, 'vector': 'CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:R'}

cvssV3_1

{'score': 7.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:R'}

cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P'}

Subscriptions

Totolink A7100ru A7100ru Firmware
cve-icon MITRE

Status: PUBLISHED

Assigner: VulDB

Published:

Updated: 2026-04-08T14:09:44.967Z

Reserved: 2026-04-06T10:26:55.603Z

Link: CVE-2026-5688

cve-icon Vulnrichment

Updated: 2026-04-08T14:09:40.982Z

cve-icon NVD

Status : Deferred

Published: 2026-04-06T23:16:28.913

Modified: 2026-04-29T01:00:01.613

Link: CVE-2026-5688

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-04-07T09:36:32Z

Weaknesses