BusyBox
BusyBox is used for several system utilities in OpenWrt like ash
shell, cp
, ls
, echo
, ping
and many others.
It provides tiny replacements with fewer options for most of the utilities from GNU Core Utilities, GNU Inetutils and other essential tools like gzip
.
All this utilities are compiled as “applets” into a single binary file /bin/busybox
.
Identify OpenWrt version through udhcp
When an OpenWrt system tries to obtain an IP using DHCP on its WAN interface, it adds a Vendor-Class option that contains the Busybox version:
Vendor-Class Option 60, length 12: “udhcp 1.28.3”
This can be used to estimate which OpenWrt version is running on a router if you don't have access to the router itself.
OpenWrt version | Busybox version |
---|---|
7.06 | 1.4.2 |
7.07 | 1.4.2 |
7.09 | 1.4.2 |
8.09 | 1.11.2 |
8.09.1 | 1.11.2 |
8.09.2 | 1.11.2 |
10.03 | 1.15.3 |
10.03.1 | 1.15.3 |
12.09 | 1.19.4 |
17.01.0 | 1.25.1 |
17.01.1 | 1.25.1 |
17.01.2 | 1.25.1 |
17.01.3 | 1.25.1 |
17.01.4 | 1.25.1 |
17.01.5 | 1.25.1 |
17.01.6 | 1.25.1 |
17.01.7 | 1.25.1 |
18.06.0 | 1.28.3 |
18.06.1 | 1.28.3 |
18.06.2 | 1.28.4 |
18.06.3 | 1.28.4 |
18.06.4 | 1.28.4 |
18.06.5 | 1.28.4 |
19.07.0 | 1.30.1 |
22.03.0 | 1.35.0 |
23.05.0 | 1.36.1 |