With TCLtools you can transform any Cisco IOS hardware into a pivoting station. It's easy to set up and use!
- TCLmap — Port scanner implementation (nmap)
- TCLproxy — Proxy server implementation
TCLproxy is a tool for pivoting through Cisco devices. It's capable to forward any TCP port or launch a proxy server.
TCLproxy v0.0.3
Usage: tclsh ./tclproxy.tcl [-L address]... [-D address]...
Proxy server implementation. Binary protocols are supported.
-L [bind_address:]port:remote_host:remote_port
Forward a remote port to a local port.
Multiple connections and multiple forwards are supported.
-D [bind_address:]port
Launch a SOCKS4a proxy server.
Forwarding between VRF tables:
-D [VRF_table_for_listening@][bind_address]:port[@VRF_table_for_outbound_connections]
-L [VRF_table_for_listening@][bind_address]:port[@VRF_table_for_outbound_connections]:remote_host:remote_port
optional arguments:
-f, --disable-eof-check Speed increases by 1-15 KB/s, but connections don't close automatically. Dangerous!
-h, --help Show this help message and exit.
-q, --disable-output Quite mode. In this mode, you can disconnect from the console without script termination. Dangerous!
-l, --low-ports Use privileged source ports. Required for NFS (source port increments from 1 to 1023 every connection)
-n, --disable-dns Do not resolve DNS names in SOCKS mode
The effect of --disable-eof-check and --disable-output options depends on hardware architecture and firmware version.
TCLproxy will not work for port scanning, use tclmap.tcl instead.
example:
$ sudo py3tftp -p 69
cisco# configure terminal
cisco(config)# scripting tcl low-memory 5242880
cisco(config)# end
cisco# copy tftp://192.168.1.10/tclproxy.tcl flash:/
cisco# tclsh tclproxy.tcl -h
cisco# tclsh tclproxy.tcl -L 5901:10.0.0.1:445 -D :5902@enterpriseVRF -D 5900
...
cisco# del flash:/tclproxy.tcl
TCL is a high-level, general-purpose, interpreted, dynamic programming language. Cisco IOS implements TCL 8.3.4:
cisco# tclsh
cisco(tcl)# puts $tcl_version
8.3
cisco(tcl)# puts $tcl_patchLevel
8.3.4
TCLtools requires privilege level 15 on the hardware.
There are four methods to upload TCL scripts:
- Copy tcl script from ftp or tftp server:
$ sudo py3tftp -p 69
or
$ python2 -m pyftpdlib
cisco# copy tftp://192.168.1.10/tclproxy.tcl flash:/
cisco# copy ftp://192.168.1.10:2121/tclproxy.tcl flash:/
cisco# tclsh tclproxy.tcl
or
cisco# tclsh ftp://192.168.1.10:2121/tclproxy.tcl
- Create new file via tclsh:
$ cat tclproxy.tcl | sed -E 's/([{}$\[])/\\\1/g'
cisco# tclsh
cisco(tcl)# puts [open "flash:tclproxy.tcl" w+] {
cisco(tcl)# ; Copy file contents onto this
cisco(tcl)# }
cisco(tcl)# exit
cisco#
cisco# tclsh tclproxy.tcl
- Set $argv var and put script code into tclsh (non-recommended):
cisco# tclsh
cisco(tcl)# set argv [list -D 1080]
cisco(tcl)# ; Copy file contents onto this
- Use "scripting tcl init" command (non-recommended):
cisco# configure terminal
cisco(config)# scripting tcl init ftp://192.168.1.10/tclproxy.tcl
cisco(config)# end
cisco# tclsh
A good practice is to set the minimum size of free memory:
cisco# configure terminal
cisco(config)# scripting tcl low-memory 5242880
cisco(config)# end
In addition to, or instead of, you can view device performance with the following commands:
cisco# show processes cpu | i Tcl
cisco# show processes mem | i Tcl
- Do not use TCLproxy for TCP/IP port scanning. Because Cisco doesn't implement -async socket option, socks server is interrupted for 30 seconds after every connection to any filtered port.
- Outdated IOS versions can redirect TCL output to another console. It's an IOS bug.
- If you disconnect from the console, TCL script stops after the next output.
Tested on Cisco 2811 / Cisco 2821 Integrated Services Router, Cisco Catalyst 2960, and Cisco Catalyst 3750-X.
You can Open a New Issue to report a bug or suggest a new feature to improve the project. Or you can drop a few lines at mohemiv@gmail.com.