Vigil@nce: Linux kernel, buffer overflow via Bluetooth L2CAP
July 2011 by Vigil@nce
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SYNTHESIS OF THE VULNERABILITY
A remote attacker can send a malicious Bluetooth L2CAP packet, in order to corrupt the kernel memory, which leads to a denial of service and possibly to code execution.
Creation date: 27/06/2011
DESCRIPTION OF THE VULNERABILITY
The L2CAP (Logical Link Control and Adaptation Protocol) protocol adapts application data (SDP, RFCOMM, TCS, etc.) before transmitting them to the HCI layer of Bluetooth.
The l2cap_config_req() function of the file net/bluetooth/l2cap_core.c processes L2CAP packets of type Configuration. However, when the header indicates a short command size, a subtraction return a negative result, and a large memory area is copied.
A remote attacker can therefore send a malicious Bluetooth L2CAP packet, in order to corrupt the kernel memory, which leads to a denial of service and possibly to code execution.
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