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Invalid memory access in the BLE L2CAP module

Moderate
nvt published GHSA-24xp-g5gf-6vvm Dec 16, 2022

Package

ble-l2cap

Affected versions

<= 4.8

Patched versions

None

Description

Impact

The Contiki-NG operating system for IoT devices contains a Bluetooth Low Energy stack. An attacker can inject a packet in this stack, which causes the implementation to dereference a NULL pointer and triggers undefined behavior.

More specifically, while processing the L2CAP protocol, the implementation maps an incoming channel ID to its metadata structure. In this structure, state information regarding credits is managed through calls to the function input_l2cap_credit in the module os/net/mac/ble/ble-l2cap.c. Unfortunately, the input_l2cap_credit function does not check that the metadata corresponding to the user-supplied channel ID actually exists, which can lead to the channel variable being set to NULL before a pointer dereferencing operation is performed.

Patches

The vulnerability has been patched in the "develop" branch of Contiki-NG, and will be included in release 4.9.

Workarounds

Users can apply the patch in Contiki-NG pull request #2253

For more information

If you have any questions or comments about this advisory:

Severity

Moderate

CVE ID

CVE-2022-41972

Weaknesses

Credits