5.1
MEDIUM
CVE-2021-47389
KVM SVM SEV Guest Context Decommission Vulnerability
Description

In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: fix missing sev_decommission in sev_receive_start DECOMMISSION the current SEV context if binding an ASID fails after RECEIVE_START. Per AMD's SEV API, RECEIVE_START generates a new guest context and thus needs to be paired with DECOMMISSION: The RECEIVE_START command is the only command other than the LAUNCH_START command that generates a new guest context and guest handle. The missing DECOMMISSION can result in subsequent SEV launch failures, as the firmware leaks memory and might not able to allocate more SEV guest contexts in the future. Note, LAUNCH_START suffered the same bug, but was previously fixed by commit 934002cd660b ("KVM: SVM: Call SEV Guest Decommission if ASID binding fails").

INFO

Published Date :

May 21, 2024, 3:15 p.m.

Last Modified :

July 9, 2024, 4:22 p.m.

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Remotely Exploitable :

No

Impact Score :

2.5

Exploitability Score :

2.5
Affected Products

The following products are affected by CVE-2021-47389 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
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-2021-47389.

URL Resource
https://git.kernel.org/stable/c/efd7866e114dcb44f86d151e843f8276b7efbc67
https://git.kernel.org/stable/c/f1815e0aa770f2127c5df31eb5c2f0e37b60fa77

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-2021-47389 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2021-47389 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 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 09, 2024

    Action Type Old Value New Value
    Added CWE CISA-ADP CWE-772
    Removed CWE CISA-ADP CWE-400
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 03, 2024

    Action Type Old Value New Value
    Added CWE CISA-ADP CWE-400
    Added CVSS V3.1 CISA-ADP AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    May. 28, 2024

    Action Type Old Value New Value
  • CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    May. 21, 2024

    Action Type Old Value New Value
    Added Description In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: fix missing sev_decommission in sev_receive_start DECOMMISSION the current SEV context if binding an ASID fails after RECEIVE_START. Per AMD's SEV API, RECEIVE_START generates a new guest context and thus needs to be paired with DECOMMISSION: The RECEIVE_START command is the only command other than the LAUNCH_START command that generates a new guest context and guest handle. The missing DECOMMISSION can result in subsequent SEV launch failures, as the firmware leaks memory and might not able to allocate more SEV guest contexts in the future. Note, LAUNCH_START suffered the same bug, but was previously fixed by commit 934002cd660b ("KVM: SVM: Call SEV Guest Decommission if ASID binding fails").
    Added Reference kernel.org https://git.kernel.org/stable/c/efd7866e114dcb44f86d151e843f8276b7efbc67 [No types assigned]
    Added Reference kernel.org https://git.kernel.org/stable/c/f1815e0aa770f2127c5df31eb5c2f0e37b60fa77 [No types assigned]
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.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-47389 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-2021-47389 weaknesses.

CVSS31 - Vulnerability Scoring System
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