Privilege Escalation Vulnerability in Linux Kernel Packages
Summary
UBUNTU-CVE-2020-25221: get_gate_page in mm/gup.c in the Linux kernel 5.7.x and 5.8.x before 5.8.7 allows privilege escalation because of incorrect reference counting (caused by gate page mishandling) of the struct page that backs the vsyscall... Affects linux versions 3.11.0-12.19 – 3.13.0-98.145. No fix is published. How to fix ↓
Check if this vulnerability affects your application
Upload a manifest or SBOM and we'll show whether you're affected, plus every other risky package in the same scan.
No signup required · Results in about 60 seconds
Background
The Linux kernel is the core component of Linux operating systems, managing system resources and facilitating communication between hardware and software. It is known for its stability, performance, and security features. However, certain versions of the kernel have been found to be vulnerable to privilege escalation due to improper handling of reference counting in the memory management subsystem.
Vulnerability Detail
The vulnerability identified as CVE-2020-25221 affects the Linux kernel versions 5.7.x and 5.8.x prior to 5.8.7. It arises from incorrect reference counting in the function get_gate_page located in mm/gup.c. This flaw allows a 64-bit process that can utilize ptrace() or process_vm_readv() to trigger a refcount underflow, leading to potential privilege escalation. Attackers could exploit this vulnerability to gain elevated permissions, compromising system integrity and security.
How To Fix
No fixed version is published for this vulnerability.
Tip — Not sure whether your app is affected? Vulert can check the versions your app actually runs. Scan free →
Workaround
As a temporary workaround, users can limit the use of ptrace() and process_vm_readv() by restricting access to these functions for untrusted processes. This can be done by modifying system permissions or using security modules like AppArmor or SELinux to enforce stricter controls.
Conclusion
CVE-2020-25221 represents a significant security risk for systems running affected versions of the Linux kernel. Users are strongly advised to update their kernel packages to the latest patched versions to mitigate this vulnerability. Additionally, implementing workarounds can provide temporary relief until updates are applied.
See every vulnerability recorded for linux →
FAQ
CVE-2020-25221 is a vulnerability in the Linux kernel that allows privilege escalation due to incorrect reference counting in memory management.
The vulnerability affects Linux kernel versions 5.7.x and 5.8.x prior to 5.8.7.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without needing to sign up.
If exploited, this vulnerability could allow attackers to gain elevated privileges, potentially compromising the entire system.
The CVSS score for CVE-2020-25221 is 7.8, indicating a high severity level.
Related vulnerabilities
Recent vulnerabilities recorded for linux.
