CVE-2026-74232
CriticalCVSS 9.8Summary
Multiple devices (including Zbtlink L3_V2_8, WE826-T2, ZBT-7628, ZBT-ZBT7621, MoreQuick MQAC-7620, AP522, AP7628, HC5661A, APG721B, HK300, MAP-N10) with specific firmware versions ship a backdoor command-and-control implant (yunmgrd) reachable over an unauthenticated cleartext UDP channel to a hardcoded C2 server. A remote unauthenticated attacker on the network path can hijack the channel and execute arbitrary commands as root, modify DNS entries, exfiltrate PPPoE credentials, and open reverse SSH tunnels.
Risk Assessment
An attacker can gain full control of the device, steal credentials, and redirect traffic, posing a serious network security threat.
Recommendation
Update device firmware to versions without the backdoor if available, and monitor UDP traffic to unknown C2 servers.
Original NVD description (English source)
Zbtlink L3_V2_8 firmware 3.0.0.4.528, Zbtlink WE826-T2 firmware 19.1101, Zbtlink ZBT-7628 firmware 1.0.0.2.007, Zbtlink ZBT-ZBT7621 firmware 1.0.0.3.001, MoreQuick MQAC-7620, MQAC-7620A, MQAP-7620, MQAP-7620A, and MQAP-7628 firmware 1.0.0.2.000, AP522 firmware 1.0.0.2.014, AP7628 and HC5661A firmware 3.0.0.4.380, APG721B firmware 19.0809, HK300 firmware 1.0.0.2.032, and MAP-N10 firmware 1.0.0.2.044 ship a backdoor command-and-control implant (yunmgrd) reachable over an unauthenticated cleartext UDP channel to a hardcoded C2 server. A remote unauthenticated attacker on the network path can hijack the channel and execute arbitrary commands as root. The attacker can also modify DNS entries, exfiltrate PPPoE credentials, and open reverse SSH tunnels.