medium CVSS 5.7 EPSS <0.1%

CVE-2022-49138·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_event: Ignore multiple conn complete events When one of the three connection complete events is received multiple times for the same handle, the device is registered multiple times which leads to memory corruptions. Therefore, consequent events for a single connection are ignored. The conn->state can hold different values, therefore HCI_CONN_HANDLE_UNSET is introduced to identify new connections. To make sure the events do not contain this or another invalid handle HCI_CONN_HANDLE_MAX and checks are introduced. Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=215497

Severity
medium
Software
Kernel
Fixed in
5.17.3
Published

How likely is exploitation

FIRST's Exploit Prediction Scoring System puts the probability of this CVE being exploited in the next 30 days at <0.1% — higher than 19% of all published CVEs. EPSS is an independent forecast of exploitation, not a severity rating: it says nothing about how much damage a successful attack does, which is what a CVSS score measures.

Affected versions

Until: 5.17.3

Fixed in: 5.17.3

How to fix this CVE

Update your Linux kernel to version 5.17.3 or later to resolve a Bluetooth connection handling flaw that causes memory corruption when duplicate connection complete events are processed. This patch introduces validation checks to prevent the kernel from registering the same Bluetooth device multiple times, which was leading to kernel memory instability.

sudo dnf update kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Step 1: Check kernel version with 'uname -r' and compare against 5.17.3; vulnerable if below this version
  2. Step 2: Confirm Bluetooth subsystem is enabled by checking 'cat /boot/config-$(uname -r) | grep CONFIG_BT'
  3. Step 3: Monitor dmesg logs for repeated 'hci_conn_complete_evt' messages for the same connection handle using 'dmesg | grep -i "hci\|bluetooth" | tail -50'
  4. Step 4: Verify the patch by checking the kernel commit hash with 'git log --oneline | grep -i "conn complete\|hci_event"' in the kernel source directory

FAQ

What is CVE-2022-49138?

This vulnerability affects the Linux kernel's Bluetooth HCI event handler, where receiving duplicate connection complete events for the same connection handle causes the device to be registered multiple times, corrupting kernel memory and destabilizing the system.

Is CVE-2022-49138 being actively exploited?

No, this vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog and no public exploits are available. It primarily affects system stability rather than security boundaries.

What versions of Kernel are affected by CVE-2022-49138?

All kernel versions prior to 5.17.3 are vulnerable. The fix was introduced in kernel 5.17.3 and backported to stable branches.

How do I check if my server is vulnerable to CVE-2022-49138?

Run 'uname -r' to check your kernel version; if it returns a version lower than 5.17.3, your system is vulnerable. Additionally, verify Bluetooth support with 'lsmod | grep bluetooth'.

Does Defensia detect CVE-2022-49138?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If the Linux kernel is installed on a monitored server, CVE-2022-49138 will appear in your dashboard with remediation steps.

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References

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