Skip to content
Noroxi
NVD / CVE Program· CNA Linux

CVE-2024-27399: Bluetooth: l2cap: fix null-ptr-deref in l2cap_chan_timeout

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.30% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 06acb75e7ed600d0bbf7bff5628aa8f24a97978c, 6466ee65e5b27161c846c73ef407f49dfa1bd1d9, 8960ff650aec70485b40771cd8e6e8c4cb467d33.

Low priority for now. Upgrade to Linux Linux 06acb75e7ed600d0bbf7bff5628aa8f24a97978c, 6466ee65e5b27161c846c73ef407f49dfa1bd1d9, 8960ff650aec70485b40771cd8e6e8c4cb467d33 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: l2cap: fix null-ptr-deref in l2cap_chan_timeout There is a race condition between l2cap_chan_timeout() and l2cap_chan_del(). When we use l2cap_chan_del() to delete the channel, the chan->conn will be set to null. But the conn could be dereferenced again in the mutex_lock() of l2cap_chan_timeout(). As a result the null pointer dereference bug will happen. The KASAN report triggered by POC is shown below: [ 472.074580] ================================================================== [ 472.075284] BUG: KASAN: null-ptr-deref in mutex_lock+0x68/0xc0 [ 472.075308] Write of size 8 at addr 0000000000000158 by task kworker/0:0/7 [ 472.075308] [ 472.075308] CPU: 0 PID: 7 Comm: kworker/0:0 Not tainted 6.9.0-rc5-00356-g78c0094a146b #36 [ 472.075308] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu4 [ 472.075308] Workqueue: events l2cap_chan_timeout [ 472.075308] Call Trace: [ 472.075308] <TASK> [ 472.075308] dump_stack_lvl+0x137/0x1a0 [ 472.075308] print_report+0x101/0x250 [ 472.075308] ? __virt_addr_valid+0x77/0x160 [ 472.075308] ? mutex_lock+0x68/0xc0 [ 472.075308] kasan_report+0x139/0x170 [ 472.075308] ? mutex_lock+0x68/0xc0 [ 472.075308] kasan_check_range+0x2c3/0x2e0 [ 472.075308] mutex_lock+0x68/0xc0 [ 472.075308] l2cap_chan_timeout+0x181/0x300 [ 472.075308] process_one_work+0x5d2/0xe00 [ 472.075308] worker_thread+0xe1d/0x1660 [ 472.075308] ? pr_cont_work+0x5e0/0x5e0 [ 472.075308] kthread+0x2b7/0x350 [ 472.075308] ? pr_cont_work+0x5e0/0x5e0 [ 472.075308] ? kthread_blkcg+0xd0/0xd0 [ 472.075308] ret_from_fork+0x4d/0x80 [ 472.075308] ? kthread_blkcg+0xd0/0xd0 [ 472.075308] ret_from_fork_asm+0x11/0x20 [ 472.075308] </TASK> [ 472.075308] ================================================================== [ 472.094860] Disabling lock debugging due to kernel taint [ 472.096136] BUG: kernel NULL pointer dereference, address: 0000000000000158 [ 472.096136] #PF: supervisor write access in kernel mode [ 472.096136] #PF: error_code(0x0002) - not-present page [ 472.096136] PGD 0 P4D 0 [ 472.096136] Oops: 0002 [#1] PREEMPT SMP KASAN NOPTI [ 472.096136] CPU: 0 PID: 7 Comm: kworker/0:0 Tainted: G B 6.9.0-rc5-00356-g78c0094a146b #36 [ 472.096136] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu4 [ 472.096136] Workqueue: events l2cap_chan_timeout [ 472.096136] RIP: 0010:mutex_lock+0x88/0xc0 [ 472.096136] Code: be 08 00 00 00 e8 f8 23 1f fd 4c 89 f7 be 08 00 00 00 e8 eb 23 1f fd 42 80 3c 23 00 74 08 48 88 [ 472.096136] RSP: 0018:ffff88800744fc78 EFLAGS: 00000246 [ 472.096136] RAX: 0000000000000000 RBX: 1ffff11000e89f8f RCX: ffffffff8457c865 [ 472.096136] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff88800744fc78 [ 472.096136] RBP: 0000000000000158 R08: ffff88800744fc7f R09: 1ffff11000e89f8f [ 472.096136] R10: dffffc0000000000 R11: ffffed1000e89f90 R12: dffffc0000000000 [ 472.096136] R13: 0000000000000158 R14: ffff88800744fc78 R15: ffff888007405a00 [ 472.096136] FS: 0000000000000000(0000) GS:ffff88806d200000(0000) knlGS:0000000000000000 [ 472.096136] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 472.096136] CR2: 0000000000000158 CR3: 000000000da32000 CR4: 00000000000006f0 [ 472.096136] Call Trace: [ 472.096136] <TASK> [ 472.096136] ? __die_body+0x8d/0xe0 [ 472.096136] ? page_fault_oops+0x6b8/0x9a0 [ 472.096136] ? kernelmode_fixup_or_oops+0x20c/0x2a0 [ 472.096136] ? do_user_addr_fault+0x1027/0x1340 [ 472.096136] ? _printk+0x7a/0xa0 [ 472.096136] ? mutex_lock+0x68/0xc0 [ 472.096136] ? add_taint+0x42/0xd0 [ 472.096136] ? exc_page_fault+0x6a/0x1b0 [ 472.096136] ? asm_exc_page_fault+0x26/0x30 [ 472.096136] ? mutex_lock+0x75/0xc0 [ 472.096136] ? mutex_lock+0x88/0xc0 [ 472.096136] ? mutex_lock+0x75/0xc0 [ 472.096136] l2cap_chan_timeo ---truncated---

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
May 14, 2024
Updated
Jun 17, 2026
EPSS
0.3% · 23th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2024-27399

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for linux records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

We use this product, ask for help

Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel
debiandebian linux
fedoraprojectfedora

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • debian debian linux10.0
  • fedoraproject fedora39
  • fedoraproject fedora40
  • linux linux kernel5.11 and later · before 5.15.159
  • linux linux kernel5.16 and later · before 6.1.91
  • linux linux kernel3.4 and later · before 4.19.314
  • linux linux kernel6.7 and later · before 6.8.10
  • linux linux kernel6.2 and later · before 6.6.31
  • linux linux kernel4.20 and later · before 5.4.276
  • linux linux kernel5.5 and later · before 5.10.217
  • linux linux kernel6.9

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 3.4affected
    • 3df91ea20e744344100b10ae69a17211fcf5b207 and later · before e137e2ba96e51902dc2878131823a96bf8e638aeaffected · git
    • 3df91ea20e744344100b10ae69a17211fcf5b207 and later · before 6466ee65e5b27161c846c73ef407f49dfa1bd1d9affected · git
    • 3df91ea20e744344100b10ae69a17211fcf5b207 and later · before 06acb75e7ed600d0bbf7bff5628aa8f24a97978caffected · git
    • 3df91ea20e744344100b10ae69a17211fcf5b207 and later · before e97e16433eb4533083b096a3824b93a5ca3aee79affected · git
    • 3df91ea20e744344100b10ae69a17211fcf5b207 and later · before 8960ff650aec70485b40771cd8e6e8c4cb467d33affected · git
    • 3df91ea20e744344100b10ae69a17211fcf5b207 and later · before 955b5b6c54d95b5e7444dfc81c95c8e013f27ac0affected · git
    • 3df91ea20e744344100b10ae69a17211fcf5b207 and later · before eb86f955488c39526534211f2610e48a5cf8ead4affected · git
    • 3df91ea20e744344100b10ae69a17211fcf5b207 and later · before adf0398cee86643b8eacde95f17d073d022f782caffected · git
    • before 3.4not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:8bpftoolbefore 4.18.0-553.30.1.el8_104.18.0-553.30.1.el8_10
AlmaLinux:8kernelbefore 4.18.0-553.30.1.el8_104.18.0-553.30.1.el8_10
AlmaLinux:8kernel-abi-stablelistsbefore 4.18.0-553.30.1.el8_104.18.0-553.30.1.el8_10
AlmaLinux:8kernel-corebefore 4.18.0-553.30.1.el8_104.18.0-553.30.1.el8_10
AlmaLinux:8kernel-cross-headersbefore 4.18.0-553.30.1.el8_104.18.0-553.30.1.el8_10
AlmaLinux:8kernel-debugbefore 4.18.0-553.30.1.el8_104.18.0-553.30.1.el8_10
AlmaLinux:8kernel-debug-corebefore 4.18.0-553.30.1.el8_104.18.0-553.30.1.el8_10
AlmaLinux:8kernel-debug-develbefore 4.18.0-553.30.1.el8_104.18.0-553.30.1.el8_10
AlmaLinux:8kernel-debug-modulesbefore 4.18.0-553.30.1.el8_104.18.0-553.30.1.el8_10
AlmaLinux:8kernel-debug-modules-extrabefore 4.18.0-553.30.1.el8_104.18.0-553.30.1.el8_10
AlmaLinux:8kernel-develbefore 4.18.0-553.30.1.el8_104.18.0-553.30.1.el8_10
AlmaLinux:8kernel-docbefore 4.18.0-553.30.1.el8_104.18.0-553.30.1.el8_10
AlmaLinux:8kernel-headersbefore 4.18.0-553.30.1.el8_104.18.0-553.30.1.el8_10
AlmaLinux:8kernel-modulesbefore 4.18.0-553.30.1.el8_104.18.0-553.30.1.el8_10
AlmaLinux:8kernel-modules-extrabefore 4.18.0-553.30.1.el8_104.18.0-553.30.1.el8_10
AlmaLinux:8kernel-toolsbefore 4.18.0-553.30.1.el8_104.18.0-553.30.1.el8_10
AlmaLinux:8kernel-tools-libsbefore 4.18.0-553.30.1.el8_104.18.0-553.30.1.el8_10
AlmaLinux:8kernel-tools-libs-develbefore 4.18.0-553.30.1.el8_104.18.0-553.30.1.el8_10
AlmaLinux:8kernel-zfcpdumpbefore 4.18.0-553.30.1.el8_104.18.0-553.30.1.el8_10
AlmaLinux:8kernel-zfcpdump-corebefore 4.18.0-553.30.1.el8_104.18.0-553.30.1.el8_10
AlmaLinux:8kernel-zfcpdump-develbefore 4.18.0-553.30.1.el8_104.18.0-553.30.1.el8_10
AlmaLinux:8kernel-zfcpdump-modulesbefore 4.18.0-553.30.1.el8_104.18.0-553.30.1.el8_10
AlmaLinux:8kernel-zfcpdump-modules-extrabefore 4.18.0-553.30.1.el8_104.18.0-553.30.1.el8_10
AlmaLinux:8perfbefore 4.18.0-553.30.1.el8_104.18.0-553.30.1.el8_10

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2024-27394May 14, 2024 · tcp: Fix Use-After-Free in tcp_ao_connect_init
    31Monitor
  • ← EarlierCVE-2024-27398May 14, 2024 · Bluetooth: Fix use-after-free bugs caused by sco_sock_timeout
    31Monitor
  • Later →CVE-2024-27400May 14, 2024 · drm/amdgpu: once more fix the call oder in amdgpu_ttm_move() v2
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux06acb75e7ed600d0bbf7bff5628aa8f24a97978cVendor (CNA)
Linux Linux6466ee65e5b27161c846c73ef407f49dfa1bd1d9Vendor (CNA)
Linux Linux8960ff650aec70485b40771cd8e6e8c4cb467d33Vendor (CNA)
Linux Linux955b5b6c54d95b5e7444dfc81c95c8e013f27ac0Vendor (CNA)
Linux Linuxadf0398cee86643b8eacde95f17d073d022f782cVendor (CNA)
Linux Linuxe137e2ba96e51902dc2878131823a96bf8e638aeVendor (CNA)
Linux Linuxe97e16433eb4533083b096a3824b93a5ca3aee79Vendor (CNA)
Linux Linuxeb86f955488c39526534211f2610e48a5cf8ead4Vendor (CNA)
almalinux:bpftool4.18.0-553.30.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel4.18.0-553.30.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-abi-stablelists4.18.0-553.30.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-core4.18.0-553.30.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-cross-headers4.18.0-553.30.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug4.18.0-553.30.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-core4.18.0-553.30.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-devel4.18.0-553.30.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules4.18.0-553.30.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules-extra4.18.0-553.30.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-devel4.18.0-553.30.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-doc4.18.0-553.30.1.el8_10 · AlmaLinux:8Package registry (OSV)
debian:linux6.1.94-1 · Debian:12Package registry (OSV)
debian:linux-5.105.10.218-1~deb10u1 · Debian:10Package registry (OSV)
red hat:bpftool0:4.18.0-553.30.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:bpftool-debuginfo0:4.18.0-553.30.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel0:4.18.0-553.30.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-abi-stablelists0:4.18.0-553.30.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-core0:4.18.0-553.30.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-debug0:4.18.0-553.30.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-debug-core0:4.18.0-553.30.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-debug-debuginfo0:4.18.0-553.30.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)

+5

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-476 · NULL Pointer Dereference

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (12 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records