CVE-2026-66747
NVD: Zbtlink router firmware ships an embedded remote-control implant, ENDLESSDOORS, present in every published build across the product line. NVD: It is the open-source ycsunjane/rctl tool built in as an OpenWrt package (librctl.so), started at boot and run as root under the process name kworker to blend in with the kernel's [kworker/*] threads. NVD: It opens no listening port; it phones home over cleartext TCP to a hardcoded command-and-control server (command channel 7000, interactive-shell callback 7001) with no authentication and no transport encryption, re-attempting contact roughly every 35 seconds.
9.3 Severity
CRITICAL EPSS
0.0058 (45) KEV
-
Source-published summary
NVD: Zbtlink router firmware ships an embedded remote-control implant, ENDLESSDOORS, present in every published build across the product line. NVD: It is the open-source ycsunjane/rctl tool built in as an OpenWrt package (librctl.so), started at boot and run as root under the process name kworker to blend in with the kernel's [kworker/*] threads. NVD: It opens no listening port; it phones home over cleartext TCP to a hardcoded command-and-control server (command channel 7000, interactive-shell callback 7001) with no authentication and no transport encryption, re-attempting contact roughly every 35 seconds.
Possible impact
Source describes code execution review · admin privilege risk. Possible impact: An attacker may gain root or administrative-level privileges on affected systems.
Affected context
Affected product or version requires source confirmation.
Remediation / advisory
Remediation reference present; patch status requires confirmation in the linked advisory.
Why it matters
Source describes code execution review · admin privilege risk. Possible impact: An attacker may gain root or administrative-level privileges on affected systems.; CVSS 9.3 (CRITICAL); EPSS percentile 45; not listed in KEV; Remediation reference present; patch status requires confirmation in the linked advisory; sources: NVD.
What to verify
Confirm affected product/version, vendor advisory, patch or mitigation, and exposure.
Exposure hint
exposure unknown
Impact tags
Urgency reasons
Source-derived note
Summary derived from NVD description; unsafe procedural detail is not shown.
Redaction metadata
- source summary used
- True
- fallback summary used
- False
- unsafe procedural detail present
- false
- raw source displayed
- false
- public summary redacted
- true
Remediation handoff
Public-safe static handoff for human/Codex remediation planning. Scan, patch, external execution, and auto remediation are disabled.
Safety note
This radar shows source-published defensive context only. Exploit procedures, exploit strings, scanner commands, and auto-remediation are not provided.