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 v4.0 vector indicates Network attack vector with Low complexity and Low privileges required (PR:L), meaning an authenticated user with standard router access can exploit this remotely without user interaction. The E:P (Exploit Maturity: Proof-of-Concept) designation combined with publicly available exploit code elevates real-world risk despite the moderate 5.3 base score. The Low impact rating (VC:L, VI:L, VA:L) suggests limited direct confidentiality, integrity, and availability impact from a single execution, yet command injection in a router's administrative interface poses serious secondary risks-attackers with authenticated access can escalate privileges, modify network configurations, install persistence mechanisms, or pivot to internal network segments. From an SSVC perspective, exploitation is proven (POC public), automatable via the CGI interface, and the technical impact is substantial for a network device. This is a priority vulnerability for any organization operating Totolink A3300R routers, particularly in edge network positions. |
| Exploit ScenarioDerived | An attacker who has obtained valid administrative credentials for the Totolink A3300R router (through credential stuffing, weak default passwords, or phishing) can access the web interface and craft a request to /cgi-bin/cstecgi.cgi with a malicious lanIp parameter containing shell commands such as |
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Alert meAnalysisAIv1 – Mar 29, 2026
Command injection in Totolink A3300R firmware versions up to 17.0.0cu.557_b20221024 allows authenticated remote attackers to execute arbitrary commands via the lanIp parameter in the setLanCfg function of /cgi-bin/cstecgi.cgi. Publicly available exploit code exists for this vulnerability. With a CVSS score of 5.3 and moderate real-world exploitability, this presents a meaningful risk to affected router installations.
RemediationAI
Users should immediately check the Totolink website (https://www.totolink.net/) for an available firmware update addressing CVE-2026-5101 and upgrade to a patched version if available. As an interim workaround pending patch availability, restrict access to the router's web administrative interface (/cgi-bin/cstecgi.cgi) to trusted IP addresses only via firewall rules or disable remote management if not required. Additionally, change default or weak administrative credentials to prevent unauthorized access to the parameter handler. If patch availability cannot be confirmed from the vendor, consider replacing the device with an alternative router or implementing network segmentation to limit the impact of potential command injection exploitation.
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 exists in the Parameter Handler component of the Totolink A3300R router firmware, specifically in the setLanCfg function accessible via the web-based CGI interface at /cgi-bin/cstecgi.cgi. The lanIp parameter is improperly validated before being processed, allowing injection of shell metacharacters that are executed by the underlying system command interpreter. This is classified as CWE-77 (Improper Neutralization of Special Elements used in a Command), a command injection flaw stemming from insufficient input sanitization in a network device's administrative interface. The affected product is identified by CPE cpe:2.3:a:totolink:a3300r and specifically version 17.0.0cu.557_b20221024.
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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 vulnerability was identified in Totolink A3300R 17.0.0cu.557_b20221024. This affects the function setLanCfg of the file /cgi-bin/cstecgi.cgi of the component Parameter Handler. The manipulation of the argument lanIp leads to command injection. Remote exploitation of the attack is possible. The exploit is publicly available and might be used.
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.
Command injection in Totolink A3300R router firmware 17.0.0cu.557_b20221024 allows unauthenticated remote attackers to e
Command injection in Totolink A3300R firmware version 17.0.0cu.557_b20221024 allows authenticated remote attackers to ex
Command injection in Totolink A3300R router firmware version 17.0.0cu.557_b20221024 allows authenticated remote attacker
Remote command injection in Totolink A3300R firmware 17.0.0cu.557_b20221024 allows authenticated remote attackers to exe
Command injection in Totolink A3300R 17.0.0cu.557_b20221024 allows authenticated remote attackers to execute arbitrary s
Command injection in Totolink A3300R firmware 17.0.0cu.557_b20221024 allows authenticated remote attackers to execute ar
Command injection in Totolink A3300R 17.0.0cu.557_b20221024 allows authenticated remote attackers to execute arbitrary c
OS command injection in Totolink A3300R firmware version 17.0.0cu.557_B20221024 allows authenticated local attackers to
EUVD-2026-17048
NVD
CVE.org
EPSS
Vulnrichment
GitHub
VulDB
Exploit-DB