CVE-2021-21781: Medium severity linux kernel vulnerability
An information disclosure flaw exists in the ARM SIGPAGE functionality of the Linux kernel. An attacker with a local account can read the contents of the sigpage, which contains previously initialized kernel memory contents. This flaw requires an attacker to read a process’s memory at a specific offset to trigger this vulnerability.
Other sources
An information disclosure vulnerability exists in the ARM SIGPAGE functionality of Linux Kernel v5.4.66 and v5.4.54. The latest version (5.11-rc4) seems to still be vulnerable. A userland application can read the contents of the sigpage, which can leak kernel memory contents. An attacker can read a process’s memory at a specific offset to trigger this vulnerability. This was fixed in kernel releases: 4.14.222 4.19.177 5.4.99 5.10.17 5.11
An information disclosure vulnerability exists in the ARM SIGPAGE functionality of Linux Kernel. A userland application can read the contents of the sigpage (A page in which signal handler information is stored), which can leak kernel memory contents. A local attacker can read a process’s memory at a specific offset to read this information leak.
Reference: https://talosintelligence.com/vulnerabilityreports/TALOS-2021-1243
— Red Hat
Affected Software
Remediation
Patch Available
Information
Event History
Frequently Asked Questions
What is CVE-2021-21781?
CVE-2021-21781 is an information disclosure vulnerability in the ARM SIGPAGE functionality of the Linux kernel.
What is the severity of CVE-2021-21781?
CVE-2021-21781 has a severity level of medium (4 out of 10).
Which versions of the Linux kernel are affected by CVE-2021-21781?
CVE-2021-21781 affects Linux Kernel versions 5.4.66 and 5.4.54.
How can an attacker exploit CVE-2021-21781?
An attacker can exploit CVE-2021-21781 by using a userland application to read the contents of the sigpage, which can leak kernel memory contents.
Are there any fixes or patches available for CVE-2021-21781?
Yes, there are fixes available for CVE-2021-21781. Please refer to the references for more information.