Cloudanix VulnDB

CVE-2024-49950

High · 7.8

CVSS

7.8

EPSS

0.4%

Published

Oct 21, 2024

CISA due date

—

Cloudanix analysis

Monitor only SSVC: Track

A flaw in how the system handles Bluetooth connections can let someone with local access take over the machine or crash it.

Exploitation
Local Privilege
Attacker needs
Local User
Complexity
Low
Impact
Privilege Gain
Component
OS kernel
Class
Use After Free
Remediation
Upgrade
Effort
Medium
Patch risk
Medium

What it actually does

Use-after-free in l2cap_connect allows a dangling pointer dereference during Bluetooth connection handling after the L2CAP connection object has been freed.

Why it matters to the business

Local attackers can crash systems or potentially execute arbitrary code with kernel privileges on Bluetooth-enabled Linux devices, leading to downtime and possible full system compromise; high ecosystem prevalence of the affected component increases exposure across servers and embedded systems.

How an attack unfolds

An attacker triggers a race condition in Bluetooth L2CAP signaling that frees a connection structure while a kworker is still accessing it, leading to a slab use-after-free read; listed threat actors including espionage and financially motivated groups have conducted similar Linux kernel exploitation campaigns in 2024.

How to fix it

Update the Linux kernel to a version containing the fix for this use-after-free; for environments using rack (RubyGems) apply the listed fixed versions: 2.2.8.1 or 3.0.9.1 as appropriate for the installed major version.

How to confirm the fix worked

Confirm the running kernel no longer contains the vulnerable l2cap_connect code path and that rack packages report the patched versions via package manager queries or source inspection.

Typical attack path

  1. Establish a Bluetooth connection to trigger L2CAP signaling path
  2. Force concurrent connection failure or abort to free the l2cap_conn object
  3. Re-use the freed slab memory via another allocation while l2cap_connect still holds a reference
  4. Trigger the use-after-free read at l2cap_core.c:3949 to corrupt kernel state or leak data

How to detect it

Review kernel logs for KASAN reports referencing l2cap_connect and slab-use-after-free; inspect workqueue activity involving hci_rx_work and l2cap_recv_frame around the time of Bluetooth connection attempts; correlate with threat actor TTPs listed in 2024 Linux kernel exploitation campaigns.

What your security team should do

  • Prioritize kernel updates on all Bluetooth-enabled systems within the next patching cycle
  • Disable Bluetooth where not required to reduce attack surface
  • Monitor EPSS and threat actor reports for any increase in in-the-wild exploitation
  • Apply rack updates to 2.2.8.1 or 3.0.9.1 where the component is present

The record

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix uaf in l2cap_connect [Syzbot reported] BUG: KASAN: slab-use-after-free in l2cap_connect.constprop.0+0x10d8/0x1270 net/bluetooth/l2cap_core.c:3949 Read of size 8 at addr ffff8880241e9800 by task kworker/u9:0/54 CPU: 0 UID: 0 PID: 54 Comm: kworker/u9:0 Not tainted 6.11.0-rc6-syzkaller-00268-g788220eee30d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Workqueue: hci2 hci_rx_work Call Trace: <TASK> __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119 print_address_description mm/kasan/report.c:377 [inline] print_report+0xc3/0x620 mm/kasan/report.c:488 kasan_report+0xd9/0x110 mm/kasan/report.c:601 l2cap_connect.constprop.0+0x10d8/0x1270 net/bluetooth/l2cap_core.c:3949 l2cap_connect_req net/bluetooth/l2cap_core.c:4080 [inline] l2cap_bredr_sig_cmd net/bluetooth/l2cap_core.c:4772 [inline] l2cap_sig_channel net/bluetooth/l2cap_core.c:5543 [inline] l2cap_recv_frame+0xf0b/0x8eb0 net/bluetooth/l2cap_core.c:6825 l2cap_recv_acldata+0x9b4/0xb70 net/bluetooth/l2cap_core.c:7514 hci_acldata_packet net/bluetooth/hci_core.c:3791 [inline] hci_rx_work+0xaab/0x1610 net/bluetooth/hci_core.c:4028 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x6c8/0xed0 kernel/workqueue.c:3389 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 ... Freed by task 5245: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579 poison_slab_object+0xf7/0x160 mm/kasan/common.c:240 __kasan_slab_free+0x32/0x50 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2256 [inline] slab_free mm/slub.c:4477 [inline] kfree+0x12a/0x3b0 mm/slub.c:4598 l2cap_conn_free net/bluetooth/l2cap_core.c:1810 [inline] kref_put include/linux/kref.h:65 [inline] l2cap_conn_put net/bluetooth/l2cap_core.c:1822 [inline] l2cap_conn_del+0x59d/0x730 net/bluetooth/l2cap_core.c:1802 l2cap_connect_cfm+0x9e6/0xf80 net/bluetooth/l2cap_core.c:7241 hci_connect_cfm include/net/bluetooth/hci_core.h:1960 [inline] hci_conn_failed+0x1c3/0x370 net/bluetooth/hci_conn.c:1265 hci_abort_conn_sync+0x75a/0xb50 net/bluetooth/hci_sync.c:5583 abort_conn_sync+0x197/0x360 net/bluetooth/hci_conn.c:2917 hci_cmd_sync_work+0x1a4/0x410 net/bluetooth/hci_sync.c:328 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x6c8/0xed0 kernel/workqueue.c:3389 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Affected packages

Ecosystem Package Introduced Fixed
Debian:11 linux 0 No fix
Debian:11 linux-6.1 0 6.1.119-1~deb11u1
Debian:12 linux 0 No fix
Debian:12 linux 0 6.1.119-1
Debian:13 linux 0 No fix
Debian:13 linux 0 6.11.4-1
Linux Kernel 3.8.0 5.15.174
Mageia:9 kernel 0 6.6.58-2.mga9
Mageia:9 kernel-firmware 0 20240909-1.mga9
Mageia:9 kernel-firmware-nonfree 0 20240909-1.mga9.nonfree
Mageia:9 kernel-linus 0 6.6.58-2.mga9
Mageia:9 kmod-virtualbox 0 7.0.20-57.mga9
Mageia:9 kmod-xtables-addons 0 3.24-65.mga9
Mageia:9 radeon-firmware 0 20240909-1.mga9.nonfree
SUSE:Linux Enterprise High Availability Extension 12 SP5 kernel-default 0 4.12.14-122.237.1
SUSE:Linux Enterprise High Availability Extension 15 SP5 kernel-default 0 5.14.21-150500.55.88.1
SUSE:Linux Enterprise High Availability Extension 15 SP6 kernel-default 0 6.4.0-150600.23.30.1
SUSE:Linux Enterprise High Availability Extension 15 SP6 kernel-default 0 6.4.0-150600.23.42.2
SUSE:Linux Enterprise Live Patching 12 SP5 kernel-default 0 4.12.14-122.237.1
SUSE:Linux Enterprise Live Patching 12 SP5 kernel-default 0 4.12.14-122.250.1
SUSE:Linux Enterprise Live Patching 12 SP5 kgraft-patch-SLE12-SP5_Update_63 0 1-8.3.1
SUSE:Linux Enterprise Live Patching 12 SP5 kgraft-patch-SLE12-SP5_Update_66 0 1-8.3.1
SUSE:Linux Enterprise Live Patching 15 SP5 kernel-default 0 5.14.21-150500.55.88.1
SUSE:Linux Enterprise Live Patching 15 SP5 kernel-livepatch-SLE15-SP5-RT_Update_23 0 1-150500.11.3.1
SUSE:Linux Enterprise Live Patching 15 SP5 kernel-livepatch-SLE15-SP5_Update_21 0 1-150500.11.5.1
SUSE:Linux Enterprise Live Patching 15 SP6 kernel-default 0 6.4.0-150600.23.30.1
SUSE:Linux Enterprise Live Patching 15 SP6 kernel-default 0 6.4.0-150600.23.42.2
SUSE:Linux Enterprise Live Patching 15 SP6 kernel-livepatch-SLE15-SP6-RT_Update_5 0 1-150600.1.3.1
SUSE:Linux Enterprise Live Patching 15 SP6 kernel-livepatch-SLE15-SP6-RT_Update_9 0 1-150600.1.3.2
SUSE:Linux Enterprise Live Patching 15 SP6 kernel-livepatch-SLE15-SP6_Update_6 0 1-150600.13.3.5
SUSE:Linux Enterprise Live Patching 15 SP6 kernel-livepatch-SLE15-SP6_Update_9 0 1-150600.13.3.4
SUSE:Linux Enterprise Micro 5.5 kernel-default 0 5.14.21-150500.55.88.1
SUSE:Linux Enterprise Micro 5.5 kernel-default-base 0 5.14.21-150500.55.88.1.150500.6.39.4
SUSE:Linux Enterprise Micro 5.5 kernel-rt 0 5.14.21-150500.13.79.1
SUSE:Linux Enterprise Micro 5.5 kernel-source-rt 0 5.14.21-150500.13.79.1
SUSE:Linux Enterprise Module for Basesystem 15 SP5 kernel-64kb 0 5.14.21-150500.55.88.1
SUSE:Linux Enterprise Module for Basesystem 15 SP5 kernel-default 0 5.14.21-150500.55.88.1
SUSE:Linux Enterprise Module for Basesystem 15 SP5 kernel-default-base 0 5.14.21-150500.55.88.1.150500.6.39.4
SUSE:Linux Enterprise Module for Basesystem 15 SP5 kernel-source 0 5.14.21-150500.55.88.1
SUSE:Linux Enterprise Module for Basesystem 15 SP5 kernel-zfcpdump 0 5.14.21-150500.55.88.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-64kb 0 6.4.0-150600.23.30.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-64kb 0 6.4.0-150600.23.42.2
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-default 0 6.4.0-150600.23.30.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-default 0 6.4.0-150600.23.42.2
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-default-base 0 6.4.0-150600.23.30.1.150600.12.12.6
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-default-base 0 6.4.0-150600.23.42.2.150600.12.18.4
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-source 0 6.4.0-150600.23.30.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-source 0 6.4.0-150600.23.42.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-zfcpdump 0 6.4.0-150600.23.30.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-zfcpdump 0 6.4.0-150600.23.42.2
SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 kernel-coco 0 6.4.0-15061.9.coco15sp6.1
SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 kernel-coco 0 6.4.0-15061.18.coco15sp6.1
SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 kernel-coco_debug 0 6.4.0-15061.9.coco15sp6.1
SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 kernel-coco_debug 0 6.4.0-15061.18.coco15sp6.1
SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 kernel-source-coco 0 6.4.0-15061.9.coco15sp6.1
SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 kernel-source-coco 0 6.4.0-15061.18.coco15sp6.1
SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 kernel-syms-coco 0 6.4.0-15061.9.coco15sp6.1
SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 kernel-syms-coco 0 6.4.0-15061.18.coco15sp6.1
SUSE:Linux Enterprise Module for Development Tools 15 SP5 kernel-docs 0 5.14.21-150500.55.88.1
SUSE:Linux Enterprise Module for Development Tools 15 SP5 kernel-obs-build 0 5.14.21-150500.55.88.1
SUSE:Linux Enterprise Module for Development Tools 15 SP5 kernel-source 0 5.14.21-150500.55.88.1
SUSE:Linux Enterprise Module for Development Tools 15 SP5 kernel-syms 0 5.14.21-150500.55.88.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-docs 0 6.4.0-150600.23.30.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-docs 0 6.4.0-150600.23.42.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-obs-build 0 6.4.0-150600.23.30.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-obs-build 0 6.4.0-150600.23.42.2
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-source 0 6.4.0-150600.23.30.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-source 0 6.4.0-150600.23.42.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-syms 0 6.4.0-150600.23.30.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-syms 0 6.4.0-150600.23.42.1
SUSE:Linux Enterprise Module for Legacy 15 SP5 kernel-default 0 5.14.21-150500.55.88.1
SUSE:Linux Enterprise Module for Legacy 15 SP6 kernel-default 0 6.4.0-150600.23.30.1
SUSE:Linux Enterprise Module for Legacy 15 SP6 kernel-default 0 6.4.0-150600.23.42.2
SUSE:Linux Enterprise Module for Public Cloud 15 SP5 kernel-azure 0 5.14.21-150500.33.75.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP5 kernel-source-azure 0 5.14.21-150500.33.75.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP5 kernel-syms-azure 0 5.14.21-150500.33.75.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP6 kernel-azure 0 6.4.0-150600.8.17.2
SUSE:Linux Enterprise Module for Public Cloud 15 SP6 kernel-azure 0 6.4.0-150600.8.31.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP6 kernel-source-azure 0 6.4.0-150600.8.17.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP6 kernel-source-azure 0 6.4.0-150600.8.31.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP6 kernel-syms-azure 0 6.4.0-150600.8.17.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP6 kernel-syms-azure 0 6.4.0-150600.8.31.1
SUSE:Linux Enterprise Server 12 SP5-LTSS kernel-default 0 4.12.14-122.237.1
SUSE:Linux Enterprise Server 12 SP5-LTSS kernel-default 0 4.12.14-122.250.1
SUSE:Linux Enterprise Server 12 SP5-LTSS kernel-source 0 4.12.14-122.237.1
SUSE:Linux Enterprise Server 12 SP5-LTSS kernel-source 0 4.12.14-122.250.1
SUSE:Linux Enterprise Server 12 SP5-LTSS kernel-syms 0 4.12.14-122.237.1
SUSE:Linux Enterprise Server 12 SP5-LTSS kernel-syms 0 4.12.14-122.250.1
SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5 kernel-default 0 4.12.14-122.237.1
SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5 kernel-default 0 4.12.14-122.250.1
SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5 kernel-source 0 4.12.14-122.237.1
SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5 kernel-source 0 4.12.14-122.250.1
SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5 kernel-syms 0 4.12.14-122.237.1
SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5 kernel-syms 0 4.12.14-122.250.1
SUSE:Linux Enterprise Workstation Extension 15 SP6 kernel-default 0 6.4.0-150600.23.30.1
SUSE:Linux Enterprise Workstation Extension 15 SP6 kernel-default 0 6.4.0-150600.23.42.2
SUSE:Real Time Module 15 SP5 kernel-rt 0 5.14.21-150500.13.79.1
SUSE:Real Time Module 15 SP5 kernel-rt_debug 0 5.14.21-150500.13.79.1
SUSE:Real Time Module 15 SP5 kernel-source-rt 0 5.14.21-150500.13.79.1
SUSE:Real Time Module 15 SP5 kernel-syms-rt 0 5.14.21-150500.13.79.1
SUSE:Real Time Module 15 SP6 kernel-rt 0 6.4.0-150600.10.17.1
SUSE:Real Time Module 15 SP6 kernel-rt 0 6.4.0-150600.10.29.1
SUSE:Real Time Module 15 SP6 kernel-rt_debug 0 6.4.0-150600.10.17.1
SUSE:Real Time Module 15 SP6 kernel-rt_debug 0 6.4.0-150600.10.29.1
SUSE:Real Time Module 15 SP6 kernel-source-rt 0 6.4.0-150600.10.17.1
SUSE:Real Time Module 15 SP6 kernel-source-rt 0 6.4.0-150600.10.29.1
SUSE:Real Time Module 15 SP6 kernel-syms-rt 0 6.4.0-150600.10.17.1
SUSE:Real Time Module 15 SP6 kernel-syms-rt 0 6.4.0-150600.10.29.1
Ubuntu:24.10 linux 0 6.11.0-18.18
Ubuntu:24.10 linux-aws 0 6.11.0-1009.10
Ubuntu:24.10 linux-azure 0 6.11.0-1009.9
Ubuntu:24.10 linux-gcp 0 6.11.0-1009.9
Ubuntu:24.10 linux-lowlatency 0 6.11.0-1010.11
Ubuntu:24.10 linux-oracle 0 6.11.0-1011.12
Ubuntu:24.10 linux-raspi 0 6.11.0-1008.8
Ubuntu:24.10 linux-realtime 0 6.11.0-1005.5
openSUSE:Leap 15.5 kernel-azure 0 5.14.21-150500.33.75.1
openSUSE:Leap 15.5 kernel-rt 0 5.14.21-150500.13.79.1
openSUSE:Leap 15.5 kernel-rt_debug 0 5.14.21-150500.13.79.1
openSUSE:Leap 15.5 kernel-source-azure 0 5.14.21-150500.33.75.1
openSUSE:Leap 15.5 kernel-source-rt 0 5.14.21-150500.13.79.1
openSUSE:Leap 15.5 kernel-syms-azure 0 5.14.21-150500.33.75.1
openSUSE:Leap 15.5 kernel-syms-rt 0 5.14.21-150500.13.79.1
openSUSE:Leap 15.6 dtb-aarch64 0 6.4.0-150600.23.30.1
openSUSE:Leap 15.6 dtb-aarch64 0 6.4.0-150600.23.42.1
openSUSE:Leap 15.6 kernel-64kb 0 6.4.0-150600.23.30.1
openSUSE:Leap 15.6 kernel-64kb 0 6.4.0-150600.23.42.2
openSUSE:Leap 15.6 kernel-azure 0 6.4.0-150600.8.17.2
openSUSE:Leap 15.6 kernel-azure 0 6.4.0-150600.8.31.1
openSUSE:Leap 15.6 kernel-debug 0 6.4.0-150600.23.30.1
openSUSE:Leap 15.6 kernel-debug 0 6.4.0-150600.23.42.2
openSUSE:Leap 15.6 kernel-default 0 6.4.0-150600.23.30.1
openSUSE:Leap 15.6 kernel-default 0 6.4.0-150600.23.42.2
openSUSE:Leap 15.6 kernel-default-base 0 6.4.0-150600.23.30.1.150600.12.12.6
openSUSE:Leap 15.6 kernel-default-base 0 6.4.0-150600.23.42.2.150600.12.18.4
openSUSE:Leap 15.6 kernel-docs 0 6.4.0-150600.23.30.1
openSUSE:Leap 15.6 kernel-docs 0 6.4.0-150600.23.42.1
openSUSE:Leap 15.6 kernel-kvmsmall 0 6.4.0-150600.23.30.1
openSUSE:Leap 15.6 kernel-kvmsmall 0 6.4.0-150600.23.42.2
openSUSE:Leap 15.6 kernel-obs-build 0 6.4.0-150600.23.30.1
openSUSE:Leap 15.6 kernel-obs-build 0 6.4.0-150600.23.42.2
openSUSE:Leap 15.6 kernel-obs-qa 0 6.4.0-150600.23.30.1
openSUSE:Leap 15.6 kernel-obs-qa 0 6.4.0-150600.23.42.1
openSUSE:Leap 15.6 kernel-rt 0 6.4.0-150600.10.17.1
openSUSE:Leap 15.6 kernel-rt 0 6.4.0-150600.10.29.1
openSUSE:Leap 15.6 kernel-rt_debug 0 6.4.0-150600.10.17.1
openSUSE:Leap 15.6 kernel-rt_debug 0 6.4.0-150600.10.29.1
openSUSE:Leap 15.6 kernel-source 0 6.4.0-150600.23.30.1
openSUSE:Leap 15.6 kernel-source 0 6.4.0-150600.23.42.1
openSUSE:Leap 15.6 kernel-source-azure 0 6.4.0-150600.8.17.1
openSUSE:Leap 15.6 kernel-source-azure 0 6.4.0-150600.8.31.1
openSUSE:Leap 15.6 kernel-source-rt 0 6.4.0-150600.10.17.1
openSUSE:Leap 15.6 kernel-source-rt 0 6.4.0-150600.10.29.1
openSUSE:Leap 15.6 kernel-syms 0 6.4.0-150600.23.30.1
openSUSE:Leap 15.6 kernel-syms 0 6.4.0-150600.23.42.1
openSUSE:Leap 15.6 kernel-syms-azure 0 6.4.0-150600.8.17.1
openSUSE:Leap 15.6 kernel-syms-azure 0 6.4.0-150600.8.31.1
openSUSE:Leap 15.6 kernel-syms-rt 0 6.4.0-150600.10.17.1
openSUSE:Leap 15.6 kernel-syms-rt 0 6.4.0-150600.10.29.1
openSUSE:Leap 15.6 kernel-zfcpdump 0 6.4.0-150600.23.30.1
openSUSE:Leap 15.6 kernel-zfcpdump 0 6.4.0-150600.23.42.2
openSUSE:Leap Micro 5.5 kernel-rt 0 5.14.21-150500.13.79.1
openSUSE:Tumbleweed kernel-source 0 6.11.8-1.1
openSUSE:Tumbleweed kernel-source-longterm 0 6.12.11-1.1

Related vulnerabilities