CVE-2019-25160
📋 TL;DR
This CVE-2019-25160 is an out-of-bounds memory access vulnerability in the Linux kernel's netlabel subsystem, specifically in cipso_v4_map_lvl_valid() and netlbl_bitmap_walk() functions. It could allow local attackers to cause kernel crashes or potentially execute arbitrary code with kernel privileges. Systems running affected Linux kernel versions with netlabel/CIPSO 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 →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
Local privilege escalation to root, kernel panic causing system crash, or arbitrary code execution in kernel context leading to complete system compromise.
Likely Case
Kernel panic leading to denial of service (system crash) or local privilege escalation if an attacker can control the memory access parameters.
If Mitigated
Minimal impact if netlabel/CIPSO is disabled or systems are properly patched; otherwise, local attackers could still cause crashes.
🎯 Exploit Status
Exploitation requires local access and knowledge of triggering the specific out-of-bounds memory accesses. No public exploits known as of analysis.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in kernel commits: 1c973f9c7cc2b3caae93192fdc8ecb3f0b4ac000, 5578de4834fe0f2a34fedc7374be691443396d1f, 97bc3683c24999ee621d847c9348c75d2fe86272, c61d01faa5550e06794dcf86125ccd325bfad950, dc18101f95fa6e815f426316b8b9a5cee28a334e
Vendor Advisory: https://git.kernel.org/stable/c/1c973f9c7cc2b3caae93192fdc8ecb3f0b4ac000
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. For distributions: Use package manager (apt/yum/dnf) to install latest kernel updates. 3. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable netlabel/CIPSO
linuxIf netlabel and CIPSO are not needed, disable them to remove attack surface.
Check if netlabel is enabled: lsmod | grep netlabel
Disable module: rmmod netlabel (if loaded)
Prevent loading: echo 'blacklist netlabel' >> /etc/modprobe.d/blacklist.conf
🧯 If You Can't Patch
- Disable netlabel and CIPSO functionality if not required
- Implement strict access controls to limit local user privileges and monitor for suspicious activity
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if netlabel modules are loaded: uname -r && lsmod | grep netlabelCheck Version:
uname -rVerify Fix Applied:
Verify kernel version is updated to one containing fix commits and netlabel modules are either disabled or patched.📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs in /var/log/messages or dmesg
- OOM (Out of Memory) or segmentation fault messages related to kernel
Network Indicators:
- None - this is local exploitation only
SIEM Query:
Search for kernel panic events or segmentation faults in system logs🔗 References
- https://git.kernel.org/stable/c/1c973f9c7cc2b3caae93192fdc8ecb3f0b4ac000
- https://git.kernel.org/stable/c/5578de4834fe0f2a34fedc7374be691443396d1f
- https://git.kernel.org/stable/c/97bc3683c24999ee621d847c9348c75d2fe86272
- https://git.kernel.org/stable/c/c61d01faa5550e06794dcf86125ccd325bfad950
- https://git.kernel.org/stable/c/dc18101f95fa6e815f426316b8b9a5cee28a334e
- https://git.kernel.org/stable/c/e3713abc4248aa6bcc11173d754c418b02a62cbb
- https://git.kernel.org/stable/c/fbf9578919d6c91100ec63acf2cba641383f6c78
- https://git.kernel.org/stable/c/fcfe700acdc1c72eab231300e82b962bac2b2b2c
- https://git.kernel.org/stable/c/1c973f9c7cc2b3caae93192fdc8ecb3f0b4ac000
- https://git.kernel.org/stable/c/5578de4834fe0f2a34fedc7374be691443396d1f
- https://git.kernel.org/stable/c/97bc3683c24999ee621d847c9348c75d2fe86272
- https://git.kernel.org/stable/c/c61d01faa5550e06794dcf86125ccd325bfad950
- https://git.kernel.org/stable/c/dc18101f95fa6e815f426316b8b9a5cee28a334e
- https://git.kernel.org/stable/c/e3713abc4248aa6bcc11173d754c418b02a62cbb
- https://git.kernel.org/stable/c/fbf9578919d6c91100ec63acf2cba641383f6c78
- https://git.kernel.org/stable/c/fcfe700acdc1c72eab231300e82b962bac2b2b2c
