CVE-2021-47008
KVM: SVM: Make sure GHCB is mapped before updating
Description
In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Make sure GHCB is mapped before updating Access to the GHCB is mainly in the VMGEXIT path and it is known that the GHCB will be mapped. But there are two paths where it is possible the GHCB might not be mapped. The sev_vcpu_deliver_sipi_vector() routine will update the GHCB to inform the caller of the AP Reset Hold NAE event that a SIPI has been delivered. However, if a SIPI is performed without a corresponding AP Reset Hold, then the GHCB might not be mapped (depending on the previous VMEXIT), which will result in a NULL pointer dereference. The svm_complete_emulated_msr() routine will update the GHCB to inform the caller of a RDMSR/WRMSR operation about any errors. While it is likely that the GHCB will be mapped in this situation, add a safe guard in this path to be certain a NULL pointer dereference is not encountered.
INFO
Published Date :
Feb. 28, 2024, 9:15 a.m.
Last Modified :
Dec. 9, 2024, 6:24 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- 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-2021-47008.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-47008 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-2021-47008
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-2021-47008 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-47008 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.
-
Initial Analysis by [email protected]
Dec. 09, 2024
Action Type Old Value New Value Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE NIST CWE-476 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.11.22 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.12 up to (excluding) 5.12.5 Changed Reference Type https://git.kernel.org/stable/c/a3ba26ecfb569f4aa3f867e80c02aa65f20aadad No Types Assigned https://git.kernel.org/stable/c/a3ba26ecfb569f4aa3f867e80c02aa65f20aadad Patch Changed Reference Type https://git.kernel.org/stable/c/a3ba26ecfb569f4aa3f867e80c02aa65f20aadad No Types Assigned https://git.kernel.org/stable/c/a3ba26ecfb569f4aa3f867e80c02aa65f20aadad Patch Changed Reference Type https://git.kernel.org/stable/c/fb9e14f4f8217a0980f8da2c8ff70dee058cbe47 No Types Assigned https://git.kernel.org/stable/c/fb9e14f4f8217a0980f8da2c8ff70dee058cbe47 Patch Changed Reference Type https://git.kernel.org/stable/c/fb9e14f4f8217a0980f8da2c8ff70dee058cbe47 No Types Assigned https://git.kernel.org/stable/c/fb9e14f4f8217a0980f8da2c8ff70dee058cbe47 Patch Changed Reference Type https://git.kernel.org/stable/c/fd722a57fe0b80133dacae4e1c852ee4212f9b2e No Types Assigned https://git.kernel.org/stable/c/fd722a57fe0b80133dacae4e1c852ee4212f9b2e Patch Changed Reference Type https://git.kernel.org/stable/c/fd722a57fe0b80133dacae4e1c852ee4212f9b2e No Types Assigned https://git.kernel.org/stable/c/fd722a57fe0b80133dacae4e1c852ee4212f9b2e Patch -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Nov. 21, 2024
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/a3ba26ecfb569f4aa3f867e80c02aa65f20aadad Added Reference https://git.kernel.org/stable/c/fb9e14f4f8217a0980f8da2c8ff70dee058cbe47 Added Reference https://git.kernel.org/stable/c/fd722a57fe0b80133dacae4e1c852ee4212f9b2e -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 28, 2024
Action Type Old Value New Value -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 14, 2024
Action Type Old Value New Value -
CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Feb. 28, 2024
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Make sure GHCB is mapped before updating Access to the GHCB is mainly in the VMGEXIT path and it is known that the GHCB will be mapped. But there are two paths where it is possible the GHCB might not be mapped. The sev_vcpu_deliver_sipi_vector() routine will update the GHCB to inform the caller of the AP Reset Hold NAE event that a SIPI has been delivered. However, if a SIPI is performed without a corresponding AP Reset Hold, then the GHCB might not be mapped (depending on the previous VMEXIT), which will result in a NULL pointer dereference. The svm_complete_emulated_msr() routine will update the GHCB to inform the caller of a RDMSR/WRMSR operation about any errors. While it is likely that the GHCB will be mapped in this situation, add a safe guard in this path to be certain a NULL pointer dereference is not encountered. Added Reference Linux https://git.kernel.org/stable/c/fb9e14f4f8217a0980f8da2c8ff70dee058cbe47 [No types assigned] Added Reference Linux https://git.kernel.org/stable/c/fd722a57fe0b80133dacae4e1c852ee4212f9b2e [No types assigned] Added Reference Linux https://git.kernel.org/stable/c/a3ba26ecfb569f4aa3f867e80c02aa65f20aadad [No types assigned]