Headline
CVE-2023-23609: Improper size validation of L2CAP frames
Contiki-NG is an open-source, cross-platform operating system for Next-Generation IoT devices. Versions prior to and including 4.8 are vulnerable to an out-of-bounds write that can occur in the BLE-L2CAP module. The Bluetooth Low Energy - Logical Link Control and Adaptation Layer Protocol (BLE-L2CAP) module handles fragmentation of packets up the configured MTU size. When fragments are reassembled, they are stored in a packet buffer of a configurable size, but there is no check to verify that the packet buffer is large enough to hold the reassembled packet. In Contiki-NG’s default configuration, it is possible that an out-of-bounds write of up to 1152 bytes occurs. The vulnerability has been patched in the “develop” branch of Contiki-NG, and will be included in release 4.9. The problem can be fixed by applying the patch in Contiki-NG pull request #2254 prior to the release of version 4.9.
Impact
An out-of-bounds write can occur in the BLE-L2CAP module of the Contiki-NG operating system. The Bluetooth Low Energy - Logical Link Control and Adaptation Layer Protocol (BLE-L2CAP) module handles fragmentation of packets up the configured MTU size.
When fragments are reassembled, they are stored in a packet buffer of a configurable size, but there is no check to verify that the packet buffer is large enough to hold the reassembled packet. It is therefore possible that an out-of-bounds write occurs, which can be of up to 1152 bytes in Contiki-NG’s default configuration.
Patches
The vulnerability has been patched in the “develop” branch of Contiki-NG, and will be included in release 4.9.
Workarounds
The problem can be fixed by applying the patch in Contiki-NG pull request #2254.
For more information
If you have any questions or comments about this advisory:
Open an issue in https://github.com/contiki-ng/contiki-ng
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