CVE-2020-12654
📋 TL;DR
This vulnerability allows a remote access point to trigger a heap-based buffer overflow in the Linux kernel's mwifiex wireless driver. Attackers could potentially execute arbitrary code or cause denial of service on affected systems. The vulnerability affects Linux systems using Marvell mwifiex wireless chipsets.
💻 Affected Systems
- Linux kernel with mwifiex wireless driver
📦 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 →⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with kernel privileges leading to complete system compromise.
Likely Case
Kernel panic or system crash causing denial of service.
If Mitigated
System remains stable if wireless interface is disabled or not using vulnerable driver.
🎯 Exploit Status
Exploitation requires attacker to control a wireless access point that the victim connects to.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Linux kernel 5.5.4 and later
Vendor Advisory: http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00022.html
Restart Required: Yes
Instructions:
1. Update Linux kernel to version 5.5.4 or later. 2. Reboot system to load new kernel. 3. Verify kernel version with 'uname -r'.
🔧 Temporary Workarounds
Disable mwifiex driver
linuxBlacklist or disable the vulnerable mwifiex wireless driver
echo 'blacklist mwifiex' >> /etc/modprobe.d/blacklist.conf
rmmod mwifiex
Disable wireless interface
linuxTurn off wireless networking to prevent connection to malicious access points
ip link set wlan0 down
nmcli radio wifi off
🧯 If You Can't Patch
- Disable wireless networking entirely on affected systems
- Use wired networking only and physically disable wireless hardware
🔍 How to Verify
Check if Vulnerable:
Check kernel version with 'uname -r' and verify it's below 5.5.4. Check if mwifiex module is loaded with 'lsmod | grep mwifiex'.Check Version:
uname -rVerify Fix Applied:
Verify kernel version is 5.5.4 or higher with 'uname -r'. Check that system remains stable when connecting to wireless networks.📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- mwifiex driver crash messages in dmesg
- System crash/reboot events
Network Indicators:
- Unusual wireless connection attempts
- Connection to unknown access points
SIEM Query:
source="kernel" AND ("panic" OR "mwifiex" OR "buffer overflow")🔗 References
- http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00022.html
- http://www.openwall.com/lists/oss-security/2020/05/08/2
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.5.4
- https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=3a9b153c5591548612c3955c9600a98150c81875
- https://github.com/torvalds/linux/commit/3a9b153c5591548612c3955c9600a98150c81875
- https://lists.debian.org/debian-lts-announce/2020/06/msg00011.html
- https://lists.debian.org/debian-lts-announce/2020/06/msg00012.html
- https://lists.debian.org/debian-lts-announce/2020/06/msg00013.html
- https://security.netapp.com/advisory/ntap-20200608-0001/
- https://usn.ubuntu.com/4392-1/
- https://usn.ubuntu.com/4393-1/
- https://www.debian.org/security/2020/dsa-4698
- http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00022.html
- http://www.openwall.com/lists/oss-security/2020/05/08/2
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.5.4
- https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=3a9b153c5591548612c3955c9600a98150c81875
- https://github.com/torvalds/linux/commit/3a9b153c5591548612c3955c9600a98150c81875
- https://lists.debian.org/debian-lts-announce/2020/06/msg00011.html
- https://lists.debian.org/debian-lts-announce/2020/06/msg00012.html
- https://lists.debian.org/debian-lts-announce/2020/06/msg00013.html
- https://security.netapp.com/advisory/ntap-20200608-0001/
- https://usn.ubuntu.com/4392-1/
- https://usn.ubuntu.com/4393-1/
- https://www.debian.org/security/2020/dsa-4698
