CVE-2022-49883
Description
From CVE.org
In the Linux kernel, the following vulnerability has been resolved: KVM: x86: smm: number of GPRs in the SMRAM image depends on the image format On 64 bit host, if the guest doesn't have X86_FEATURE_LM, KVM will access 16 gprs to 32-bit smram image, causing out-ouf-bound ram access. On 32 bit host, the rsm_load_state_64/enter_smm_save_state_64 is compiled out, thus access overflow can't happen.
Statement
A memory corruption vulnerability exists in the KVM x86 implementation, where the wrong number of General Purpose Registers (GPRs) is accessed in the System Management Mode (SMM) save/restore logic depending on guest architecture. On 64-bit hosts running 32-bit guests without the X86_FEATURE_LM feature, KVM may access out-of-bounds memory when reading or writing the SMRAM image, due to assuming a 64-bit GPR layout. This issue can only be triggered by a local, privileged guest user with access to SMM context or control over crafted guest state in a virtualized environment.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.3 | 7.1 | 7.1 |
| Attack Vector | Local | Local | Local |
| Attack Complexity | High | Low | Low |
| Privileges Required | High | Low | Low |
| User Interaction | None | None | None |
| Scope | Changed | Unchanged | Unchanged |
| Confidentiality | None | High | High |
| Integrity Impact | None | None | None |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
