Vulnerabilities > CVE-2017-7726 - Improper Certificate Validation vulnerability in Ismartalarm Cubeone Firmware

047910
CVSS 5.0 - MEDIUM
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
PARTIAL
Availability impact
NONE
network
low complexity
ismartalarm
CWE-295

Summary

iSmartAlarm cube devices have an SSL Certificate Validation Vulnerability.

Vulnerable Configurations

Part Description Count
OS
Ismartalarm
1
Hardware
Ismartalarm
1

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Creating a Rogue Certificate Authority Certificate
    An attacker exploits a weakness in the MD5 hash algorithm (weak collision resistance) to generate a certificate signing request (CSR) that contains collision blocks in the "to be signed" part. The attacker specially crafts two different, but valid X.509 certificates that when hashed with the MD5 algorithm would yield the same value. The attacker then sends the CSR for one of the certificates to the Certification Authority which uses the MD5 hashing algorithm. That request is completely valid and the Certificate Authority issues an X.509 certificate to the attacker which is signed with its private key. An attacker then takes that signed blob and inserts it into another X.509 certificate that the attacker generated. Due to the MD5 collision, both certificates, though different, hash to the same value and so the signed blob works just as well in the second certificate. The net effect is that the attackers' second X.509 certificate, which the Certification Authority has never seen, is now signed and validated by that Certification Authority. To make the attack more interesting, the second certificate could be not just a regular certificate, but rather itself a signing certificate. Thus the attacker is able to start their own Certification Authority that is anchored in its root of trust in the legitimate Certification Authority that has signed the attackers' first X.509 certificate. If the original Certificate Authority was accepted by default by browsers, so will now the Certificate Authority set up by the attacker and of course any certificates that it signs. So the attacker is now able to generate any SSL certificates to impersonate any web server, and the user's browser will not issue any warning to the victim. This can be used to compromise HTTPS communications and other types of systems where PKI and X.509 certificates may be used (e.g., VPN, IPSec) .

Packetstorm

data sourcehttps://packetstormsecurity.com/files/download/143368/ismartalarmcubeone-exec.txt
idPACKETSTORM:143368
last seen2017-07-15
published2017-07-14
reporterIlia Shnaidman
sourcehttps://packetstormsecurity.com/files/143368/iSmartAlarm-CubeOne-Remote-Command-Execution.html
titleiSmartAlarm CubeOne Remote Command Execution

Seebug

bulletinFamilyexploit
description### Vendor: iSmartAlarm, inc. ### Product: iSmartAlarm cube - All iSmartAlarm is one of the leading IoT manufactures in the domain of smart alarm systems. It provides a fully integrated alarm system with siren, smart cameras and locks. It functions like any alarm system, but with the benefits of a connected device: alerts pop up on your phone, offering you full remote control via mobile app wherever you are. ### Vulnerability Type: Authentication Bypass ### CVE Reference: CVE-2017-7728 ### Security Issue: On iSmartAlarm cube devices, there is an authentication bypass. The vulnerability can lead to remote execution of alarm's commands; setting the alarm on/off and activating the alarm siren. ### Additional Information: * First the app and the cube authenticate by using sophisticated 4 way handshake. Looks like that: ``` App ISAT\x01\x00*3\x01\x00*7 Cube ISAT\x02\x00*3\x01\x00*3\x10\x00*3 + "Cube generated Secret Key" ``` * Encryption algorithm: With the "Secret key" and the IPU (encryption key) the app decrypts a key using XXTEA encryption algorithm (funny thing is that ismartalarm implementation is broken). After that, the algorithm takes the output of the XXTEA enc and then reverses the output. This is the "new key"! So now, we got the encryption key, and we can do whatever we want with the alarm. * The app sends command as follows to proceed with the authentication: ``` App ISAT\x03\x00*3\x01\x00*3\x10\x00*3 + "new key" Cube ISAT\x04\x00*3\x01\x00*3\x01\x00*3\x01 ``` * NOW WE ARE AUTHENTICATED. we can now send one of the following commands to the cube Disarming the alarm "Disarm mode": ``` ISATP\x00*3\x01\x00*3\x03\x00*3\x01\x002 Arming the alarm "Arm mode": ISATP\x00*3\x01\x00*3\x03\x00*3\x01\x000 Activate alarm's siren "Panic mode": ISATP\x00*3\x01\x00*3\x03\x00*3\x01\x003 ``` ### Attack Vectors: After authentication, using the above protocol will allow full control of the alarm. When iSmartAlarm's mobile app connected to the same network as the iSmartAlarm's cube, their authentication and then communication are made on port tcp/12345 in PLAIN TEXT. Obtaining encryption key is done by using CVE-2017-7726. After setting the MITM a POST request is made to the following api: https://api.ismartalarm.com:8443/api/GetIpuEnr.ashx From there an attacker can obtain the encryption key. After obtaining the encryption key, using the above protocol will allow an attacker a full control over the alarm system.
idSSV:97273
last seen2018-06-26
modified2018-05-08
published2018-05-08
reporterMy Seebug
sourcehttps://www.seebug.org/vuldb/ssvid-97273
titleAuthentication Bypass allows alarm's commands execution in iSmartAlarm(CVE-2017-7728)