8.8
HIGH CVSS 3.1
CVE-2021-4093
KVM AMD SEV-ES Guest-to-Host Escape Vulnerability
Description

A flaw was found in the KVM's AMD code for supporting the Secure Encrypted Virtualization-Encrypted State (SEV-ES). A KVM guest using SEV-ES can trigger out-of-bounds reads and writes in the host kernel via a malicious VMGEXIT for a string I/O instruction (for example, outs or ins) using the exit reason SVM_EXIT_IOIO. This issue results in a crash of the entire system or a potential guest-to-host escape scenario.

INFO

Published Date :

Feb. 18, 2022, 6:15 p.m.

Last Modified :

Nov. 21, 2024, 6:36 a.m.

Remotely Exploit :

No

Source :

[email protected]
Affected Products

The following products are affected by CVE-2021-4093 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
1 Canonical ubuntu_linux
1 Redhat enterprise_linux
1 Fedoraproject fedora
: Total Affected Vendor : 4 | Products : 4
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 2.0 HIGH [email protected]
CVSS 3.1 HIGH [email protected]
Solution
Follow the instructions below to mitigate the CVE-2021-4093 vulnerability.
There is no known solution at this time.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2021-4093.

URL Resource
https://bugs.chromium.org/p/project-zero/issues/detail?id=2222 Exploit Mailing List Patch Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2028584 Issue Tracking Patch Third Party Advisory
https://bugs.chromium.org/p/project-zero/issues/detail?id=2222 Exploit Mailing List Patch Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2028584 Issue Tracking Patch Third Party Advisory
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-4093 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2021-4093 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-4093 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2021-4093 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Nov. 21, 2024

    Action Type Old Value New Value
    Added Reference https://bugs.chromium.org/p/project-zero/issues/detail?id=2222
    Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2028584
  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • CVE Modified by [email protected]

    Nov. 07, 2023

    Action Type Old Value New Value
    Removed CWE Red Hat, Inc. CWE-787
  • Reanalysis by [email protected]

    Jan. 19, 2023

    Action Type Old Value New Value
    Changed CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions up to (excluding) 5.15 OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.14.16
  • Initial Analysis by [email protected]

    Mar. 01, 2022

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:L/AC:L/Au:N/C:C/I:C/A:C)
    Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
    Changed Reference Type https://bugs.chromium.org/p/project-zero/issues/detail?id=2222 No Types Assigned https://bugs.chromium.org/p/project-zero/issues/detail?id=2222 Exploit, Mailing List, Patch, Third Party Advisory
    Changed Reference Type https://bugzilla.redhat.com/show_bug.cgi?id=2028584 No Types Assigned https://bugzilla.redhat.com/show_bug.cgi?id=2028584 Issue Tracking, Patch, Third Party Advisory
    Added CWE NIST CWE-787
    Added CWE NIST CWE-125
    Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions up to (excluding) 5.15
    Added CPE Configuration OR *cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
    Added CPE Configuration OR *cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
    Added CPE Configuration OR *cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:* *cpe:2.3:o:canonical:ubuntu_linux:21.10:*:*:*:*:*:*:*
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 8.8
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact
Base CVSS Score: 7.2
Access Vector
Access Complexity
Authentication
Confidentiality Impact
Integrity Impact
Availability Impact
Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.10 }} -0.00%

score

0.28497

percentile