CVE-2020-10781 Explained : Impact and Mitigation
Learn about CVE-2020-10781, a flaw in the Linux Kernel ZRAM module allowing local users to consume system memory, potentially leading to system inoperability. Find mitigation steps here.
A flaw in the Linux Kernel before 5.8-rc6 allows a local user to consume system memory, potentially leading to the activation of the Out-of-Memory killer.
Understanding CVE-2020-10781
This CVE identifies a vulnerability in the ZRAM kernel module of the Linux Kernel.
What is CVE-2020-10781?
The vulnerability allows a local user to create ZRAM device nodes in the /dev/ directory by reading a specific file, leading to unaccounted kernel memory allocation.
The Impact of CVE-2020-10781
Continuously reading the device may exhaust system memory, triggering the Out-of-Memory killer to terminate processes and potentially rendering the system inoperable.
Technical Details of CVE-2020-10781
The following technical details provide insight into the vulnerability.
Vulnerability Description
- User with local account can create ZRAM device nodes in /dev/ directory
- Reading specific file triggers unaccounted kernel memory allocation
Affected Systems and Versions
- Vendor: Linux Kernel
- Product: kernel
- Affected Version: before 5.8-rc6
Exploitation Mechanism
- Local user reads /sys/class/zram-control/hot_add file
- Creation of ZRAM device nodes in /dev/ directory
Mitigation and Prevention
Protect systems from CVE-2020-10781 with the following measures.
Immediate Steps to Take
- Apply patches provided by the Linux Kernel
- Monitor system memory usage regularly
Long-Term Security Practices
- Restrict access to sensitive system files
- Implement least privilege access controls
Patching and Updates
- Regularly update the Linux Kernel to versions beyond 5.8-rc6 to mitigate the vulnerability.