> Tenda is a supplier of home and business network devices such as routers, switches, wireless access points, and video surveillance equipment.

I was unfamiliar with Tenda.

> Shenzhen Tenda Technology Co.,Ltd. ( https://www.tendacn.com/us/profile )

Tenda may just rebrand, right? It seems like many chinese brands will either rebrand or have a 'competing' brand with the same internals but different externals. (I have no idea if Tenda does this, I've just seen it previously. Specifically with security cameras)

I wish the authors provided some method for checking this vulnerability other than fw version. It seems like Tenda could just change the password and say "yep! all safe now"

The article doesn't disclose the value of "sys.rzadmin.password", but this writeup from 2022 does:

https://boschko.ca/tenda_ac1200_router/

Spoiler: it's "rzadmin". And it looks like there are a bunch of other goodies in the firmware, too.

The US/Israel would never do such a thing, buy UniFi/Fortinet/Palo Alto!

Have used their travel wifi product back when hotel wifi was a strange beast. Wouldn't expect to need it now eSIM and ubiquitous internet travel pricing means the hotel wifi may be the LEAST valid path to access things.

I have a free give-away mikrotik unit in the same price bracket (literally free: they were both conference give-aways) it's physically smaller and it runs what appears to be their mainline code. Say what you like about microtik for quality, they provide pretty much every knob and frob you could want.

My ifconfig is simple: if it's made in Shenzhen, throw it out

So will this finally be treated as sabotage/criminal hacking, or is it just yet another example of letting manufacturers do whatever they want to their customers without any punishment? Meanwhile if I find and publish the emails of Tenda customers that they accidentally left unprotected, I get raided by the FBI.

It looks like recent Tenda hardware/firmware is encrypted per below examples, making it harder to audit.

binwalk US_AC10V6.0si_V16.03.62.09_multi_TDE01.bin

  DECIMAL       HEXADECIMAL     DESCRIPTION
  --------------------------------------------------------------------------------
  516           0x204           OpenSSL encryption, salted, salt: 0x436999A39FECA649

  DECIMAL       HEXADECIMAL     DESCRIPTION
  --------------------------------------------------------------------------------
  516           0x204           OpenSSL encryption, salted, salt: 0x81235B7D4130B6AB

binwalk US_W18EV2_kf_V16.01.0.20\(4766\)_HighPower\ \(1\).bin

  DECIMAL       HEXADECIMAL     DESCRIPTION
  --------------------------------------------------------------------------------
  64            0x40            uImage header, header size: 64 bytes, header CRC: 0x95335734, created: 2026-06-16 09:09:35, image size: 2159135 bytes, Data Address: 0x80100000, Entry Point: 0x805F41C0, data CRC: 0x5ABEDB00, OS: Linux, CPU: MIPS, image type: OS Kernel Image, compression type: lzma, image name: "MIPS Tenda Linux-4.14.90"
  128           0x80            LZMA compressed data, properties: 0x6D, dictionary size: 8388608 bytes, uncompressed size: 6947248 bytes
  2159263       0x20F29F        Squashfs filesystem, little endian, version 4.0, compression:xz, size: 8971644 bytes, 847 inodes, blocksize: 1048576 bytes, created: 2026-06-16 08:53:20

  sys.rzadmin.username=rzadmin
  sys.rzadmin.password=cnphZG1pbg==  (ed: base64 decoded: rzadmin)
  sys.guest.username=guest
  sys.guest.password=Z3Vlc3Q=  (ed: base64 decoded: guest)

  sys.rzadmin.username=rzadmin
  sys.rzadmin.password=cnphZG1pbg==  (ed: base64 decoded: rzadmin)

Also for fun there is a function imsd_upload_log_v1 in /bin/imsd that collects SSIDs, MACs, IP addresses, sys.admin.username, sys.rzadmin.username, timezone, and another function imsd_remote_pwd_get in /bin/imsd that retrieves sys.admin.password. Related library /lib/lubucapi.so also looks like a fun binary to inspect more closely as it contains a command set that seemingly allows either cloud management of Tenda routers and/or remote debugging, and possibly is why imsd_remote_pwd_get exists in /bin/imsd

And this is why I handroll my own routers/firewalls, using commodity hardware and a Linux distribution.

Not to sound too alarming. But

Security holes in networking equipment

Affects not just the compromised devices.

Up and out the back door, any 'ol time.

Chinese undocumented auth: commies tryna steal mah api tokenz

US undocumented auth: legitimate usecase for out of band support nothing to see here

Yet another Chinese company selling backdoor'd product. Surprise surprise...