Rapid7 Vulnerability & Exploit Database

Amazon Linux AMI: CVE-2021-26932: Security patch for kernel (ALAS-2021-1487)

Free InsightVM Trial No Credit Card Necessary
2024 Attack Intel Report Latest research by Rapid7 Labs
Back to Search

Amazon Linux AMI: CVE-2021-26932: Security patch for kernel (ALAS-2021-1487)

Severity
2
CVSS
(AV:L/AC:M/Au:N/C:N/I:N/A:P)
Published
02/17/2021
Created
03/23/2021
Added
03/20/2021
Modified
10/14/2022

Description

An issue was discovered in the Linux kernel 3.2 through 5.10.16, as used by Xen. Grant mapping operations often occur in batch hypercalls, where a number of operations are done in a single hypercall, the success or failure of each one is reported to the backend driver, and the backend driver then loops over the results, performing follow-up actions based on the success or failure of each operation. Unfortunately, when running in PV mode, the Linux backend drivers mishandle this: Some errors are ignored, effectively implying their success from the success of related batch elements. In other cases, errors resulting from one batch element lead to further batch elements not being inspected, and hence successful ones to not be possible to properly unmap upon error recovery. Only systems with Linux backends running in PV mode are vulnerable. Linux backends run in HVM / PVH modes are not vulnerable. This affects arch/*/xen/p2m.c and drivers/xen/gntdev.c.

Solution(s)

  • amazon-linux-upgrade-kernel

With Rapid7 live dashboards, I have a clear view of all the assets on my network, which ones can be exploited, and what I need to do in order to reduce the risk in my environment in real-time. No other tool gives us that kind of value and insight.

– Scott Cheney, Manager of Information Security, Sierra View Medical Center

;