CVE-2022-50310
📋 TL;DR
This CVE describes a use-after-free vulnerability in the Linux kernel's IPv6 multicast routing subsystem. When network namespace initialization fails, the kernel attempts to access already-freed memory, potentially leading to kernel crashes or local privilege escalation. Systems running affected Linux kernel versions with IPv6 enabled are vulnerable.
💻 Affected Systems
- Linux kernel
📦 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...
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 panic leading to system crash, or potential local privilege escalation allowing an attacker to gain root access.
Likely Case
Kernel crash or system instability when network namespace operations fail during setup.
If Mitigated
No impact if the vulnerable code path isn't triggered or if IPv6 is disabled.
🎯 Exploit Status
Exploitation requires local access and triggering specific error conditions during network namespace creation. The vulnerability is in error handling code paths.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patched in kernel commits 1ca695207ed2271ecbf8ee6c641970f621c157cc and 22a68c3b9362eaac7b035eba09e95e6b3f7a912c
Vendor Advisory: https://git.kernel.org/stable/c/1ca695207ed2271ecbf8ee6c641970f621c157cc
Restart Required: Yes
Instructions:
1. Update to a kernel version containing the fix commits. 2. Check with your Linux distribution for available security updates. 3. Reboot the system after kernel update.
🔧 Temporary Workarounds
Disable IPv6 multicast routing
linuxPrevent loading of the vulnerable ip6mr module
echo 'blacklist ip6mr' >> /etc/modprobe.d/blacklist.conf
rmmod ip6mr
Disable IPv6 entirely
linuxCompletely disable IPv6 to avoid the vulnerable code path
echo 'net.ipv6.conf.all.disable_ipv6 = 1' >> /etc/sysctl.conf
sysctl -p
🧯 If You Can't Patch
- Restrict local user access to prevent potential privilege escalation attempts
- Monitor system logs for kernel panic or crash events related to network namespace operations
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if IPv6 multicast routing is enabled: 'uname -r' and 'lsmod | grep ip6mr'Check Version:
uname -rVerify Fix Applied:
Verify kernel version is patched: 'uname -r' should show version containing fix commits. Check with distribution security advisories.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- KASAN use-after-free reports in dmesg
- Network namespace creation failures
Network Indicators:
- Unusual network namespace creation attempts by local users
SIEM Query:
source="kernel" AND ("KASAN: use-after-free" OR "ip6mr_sk_done" OR "addrconf_init_net failed")