-----BEGIN PGP SIGNED MESSAGE-----
MSL-2008-002 - HTC Touch vCard over IP Denial of Service
HTC Touch vCard over IP Denial of Service
Touch Pro, Touch Cruise
Denial of Service
HTC Touch Pro, HTC Touch Cruiser
UDP/9204 port is open and reachable both via WiFi and GPRS/UMTS
connection when the device is capable of sending and receiving SMS.
Port is always open on the Touch Pro, while on Touch Cruiser the port is
open when the SMS application is running.
UDP/9204 is associated with the service WAP-vCard and is used for
sending vCard files to the device, that are displayed as normal SMS to
By flooding the device with multiple vCards it is possible to perform a
Denial of Service attack that affects usability, SMS handling and
By sending large number of vCards an attacker can achieve significant
device slowdown, making the UI sluggish and hard to use.
In some cases WiFi connections may be dropped (when vCards are sent via
WiFi), effectively disconnecting the device from the network.
On Touch Cruiser devices, SMS inbox can be completely filled by sending
more then 450 large vCards (size 32K).
The device will not be able to receive SMS anymore or to access the
message stored inside the device until SMS deletion occurs.
Additionally, when large vCards are sent, no acoustic notification (ring
tones) will be played upon incoming messages, making the attack more
silent and less noticeable by an user.
Battery removal may be needed, in some cases, for restoring normal
Manual deletion of all received SMS requires a very long time, making
the deletion of all the SMS the most viable option, but leading to loss
of all received SMS and requiring in any case a large amount of time
The faster option for restoring the device is performing a hard reset of
the device, leading to the loss of all the content saved on the handset.
The attack can be easily carried in all the scenarios where the device
IP stack is accessible to an attacker, such as Wireless LANs and Mobile
Networks assigning public IP addresses without any firewall protection.
Solutions & Workaround:
A personal firewall solution can be used for denying unwanted access to
the port, effectively avoiding possible attacks.
2008-12-03: Issue discovery
2008-12-05: Initial Vendor Notification: Point of Contact requested via
contact form on website (No suitable e-mail available)
2008-12-14: Vendor Response: Customer support answered without providing
any suitable contact for vulnerability communication
2008-12-19: Public Disclosure
Mobile Security Lab