CVE-2023-52703

5.5 MEDIUM

📋 TL;DR

This CVE involves an uninitialized variable being passed to error handling code in the Linux kernel's Kalmia USB network driver. The vulnerability could lead to kernel memory disclosure or system instability when USB bulk transfer errors occur. It affects Linux systems using the kalmia USB network driver.

💻 Affected Systems

Products:
  • Linux Kernel
Versions: Specific affected versions not explicitly stated in CVE, but patches exist in stable kernel trees.
Operating Systems: Linux
Default Config Vulnerable: ⚠️ Yes
Notes: Only affects systems using the kalmia USB network driver (drivers/net/usb/kalmia.c). Requires USB network device that triggers bulk transfer errors.

📦 What is this software?

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

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Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Kernel memory disclosure leading to information leakage, potential privilege escalation, or system crash/panic.

🟠

Likely Case

Kernel warning messages, system instability, or denial of service when USB network devices encounter errors.

🟢

If Mitigated

Minor system logging or no impact if error conditions don't occur.

🌐 Internet-Facing: LOW - Requires local USB device access and specific error conditions.
🏢 Internal Only: LOW - Requires physical or local USB device access and specific error conditions.

🎯 Exploit Status

Public PoC: ✅ No
Weaponized: NO
Unauthenticated Exploit: ✅ No
Complexity: HIGH

Exploitation requires triggering specific USB bulk transfer error conditions and local access to USB device. Reported by syzbot fuzzer.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Patched in Linux kernel stable releases (commits: 02df3170c04a, 1b5de7d44890, 338f826d3afe, 525bdcb0838d, 723ef7b66f37)

Vendor Advisory: https://git.kernel.org/stable/c/02df3170c04a8356cd571ab9155a42f030190abc

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version from official kernel.org or distribution repositories. 2. Reboot system to load new kernel.

🔧 Temporary Workarounds

Disable kalmia USB driver

linux

Prevent loading of vulnerable kalmia USB network driver module

echo 'blacklist kalmia' >> /etc/modprobe.d/blacklist.conf
rmmod kalmia

🧯 If You Can't Patch

  • Avoid using USB network devices that use kalmia driver
  • Monitor system logs for kernel warnings related to USB bulk transfers

🔍 How to Verify

Check if Vulnerable:

Check if kalmia module is loaded: lsmod | grep kalmia. Check kernel version against patched releases.

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version includes patched commits. Check that kalmia module functions without error.

📡 Detection & Monitoring

Log Indicators:

  • Kernel warnings about uninitialized variables in kalmia_send_init_packet
  • USB bulk transfer error messages
  • Kernel oops or panic related to USB networking

Network Indicators:

  • USB network device connectivity issues

SIEM Query:

kernel: *kalmia* OR *usb_bulk_msg* error OR uninitialized

🔗 References

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