Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A05:2025 - Injection
ASVS 5.0
V1 - Encoding and Sanitization Command injection prevention
MITRE ATT&CK
1 technique across 1 tactic: Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | The CVSS vector (AV:N/AC:L/PR:L/UI:N/S:U) indicates network-accessible attack with low complexity requiring authenticated privileges but no user interaction. The medium CVSS score of 6.3 reflects limited scope (single system impact) and partial confidentiality/integrity/availability compromise. However, the presence of publicly available exploit code significantly increases practical risk despite the authentication requirement. The PR:L (authenticated) requirement does not substantially mitigate risk in home/small-business router environments where default credentials are often unchanged or shared among trusted users. The E:P (exploit proof-of-concept) rating in the CVSS vector confirms POC availability. Real-world risk is elevated because routers are persistent, always-on targets with potential for lateral network movement after compromise, making this a practical priority for affected deployments despite the 'medium' CVSS label. |
| Exploit ScenarioDerived | An authenticated user on the same network or with network access to the router's web interface (e.g., a user with default credentials not changed by the administrator) could craft a malicious HTTP request to /cgi-bin/cstecgi.cgi with a shell command embedded in the qos_up_bw parameter, such as 'qos_up_bw=$(malicious_command)' or similar command injection payload. The setSmartQosCfg function would then execute the injected command with the privileges of the CGI process, potentially allowing the attacker to modify router configuration, exfiltrate network traffic logs, or pivot to other network-connected devices. Publicly available exploit code on GitHub (referenced in VulDB submission) lowers the barrier for non-expert attackers. |
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Alert meAnalysisAIv1 – Mar 30, 2026
Command injection in Totolink A3300R 17.0.0cu.557_b20221024 allows authenticated remote attackers to execute arbitrary system commands via the qos_up_bw parameter in the setSmartQosCfg function of /cgi-bin/cstecgi.cgi. The vulnerability has a CVSS score of 6.3 (medium severity) with low attack complexity, and publicly available exploit code exists, though no active exploitation via CISA KEV has been confirmed at time of analysis.
RemediationAI
Users should immediately contact Totolink for patched firmware versions, as no specific vendor-released patch version is referenced in available data. In the interim, restrict network access to the router's management interface (typically port 80/443) to trusted IP addresses only, change default administrative credentials if not already done, and consider disabling remote management features if not required. Firmware updates, when available, should be obtained exclusively from Totolink's official website at https://www.totolink.net/. Organizations managing multiple A3300R units should prioritize patching and credential rotation, as the low attack complexity and public POC availability create elevated attack probability for networked environments.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in euvd
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
The vulnerability resides in the Parameter Handler component of Totolink's web-based management interface (cstecgi.cgi), specifically in the setSmartQosCfg function which handles Quality of Service bandwidth configuration. The root cause is improper input validation of the qos_up_bw parameter, classified as CWE-77 (Improper Neutralization of Special Elements used in a Command), allowing an attacker to inject shell metacharacters or command separators. The affected device is the Totolink A3300R wireless router, a consumer-grade networking device that exposes this CGI endpoint via HTTP/HTTPS without sufficient input sanitization.
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Severity by source
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
Lifecycle Timeline
4DescriptionCVE.org
A security flaw has been discovered in Totolink A3300R 17.0.0cu.557_b20221024. This vulnerability affects the function setSmartQosCfg of the file /cgi-bin/cstecgi.cgi of the component Parameter Handler. The manipulation of the argument qos_up_bw results in command injection. The attack can be executed remotely. The exploit has been released to the public and may be used for attacks.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
OS command injection occurs when an application passes unsanitized user input directly into system shell commands.
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EUVD-2026-17050
GHSA-h2wr-p8mq-wj29
NVD
CVE.org
EPSS
Vulnrichment
VulDB
Exploit-DB