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exploitDog

fstec логотип

BDU:2025-07344

Опубликовано: 10 июн. 2021
Источник: fstec
CVSS3: 6.6
CVSS2: 6.2
EPSS Низкий

Описание

Уязвимость функции emulator_get_hflags() модуля arch/x86/kvm/x86.c подсистемы виртуализации на платформе x86 ядра операционной системы Linux связана с разыменованием указателя NULL. Эксплуатация уязвимости может позволить нарушителю оказать воздействие на целостность и доступность защищаемой информации

Вендор

Сообщество свободного программного обеспечения

Наименование ПО

Linux

Версия ПО

от 5.11 до 5.12.12 включительно (Linux)
от 5.5 до 5.10.45 включительно (Linux)
от 5.1 до 5.4.127 включительно (Linux)

Тип ПО

Операционная система

Операционные системы и аппаратные платформы

Сообщество свободного программного обеспечения Linux от 5.11 до 5.12.12 включительно
Сообщество свободного программного обеспечения Linux от 5.5 до 5.10.45 включительно
Сообщество свободного программного обеспечения Linux от 5.1 до 5.4.127 включительно

Уровень опасности уязвимости

Средний уровень опасности (базовая оценка CVSS 2.0 составляет 6,2)
Средний уровень опасности (базовая оценка CVSS 3.1 составляет 6,6)

Возможные меры по устранению уязвимости

В условиях отсутствия обновлений безопасности от производителя рекомендуется придерживаться "Рекомендаций по безопасной настройке операционных систем LINUX", изложенных в методическом документе ФСТЭК России, утверждённом 25 декабря 2022 года.
Использование рекомендаций:
Для Linux:
https://git.kernel.org/stable/c/cbb425f62df9df7abee4b3f068f7ed6ffc3561e2
https://git.kernel.org/stable/c/669a8866e468fd020d34eb00e08cb41d3774b71b
https://git.kernel.org/stable/c/df9a40cfb3be2cbeb1c17bb67c59251ba16630f3
https://git.kernel.org/stable/c/78fcb2c91adfec8ce3a2ba6b4d0dda89f2f4a7c6
https://lore.kernel.org/linux-cve-announce/2024052138-CVE-2021-47230-e1ff@gregkh/
https://git.kernel.org/linus/78fcb2c91adfec8ce3a2ba6b4d0dda89f2f4a7c6
https://git.linuxtesting.ru/pub/scm/linux/kernel/git/lvc/linux-stable.git/commit/?h=v5.10.176-lvc1&id=669a8866e468fd020d34eb00e08cb41d3774b71b
https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4.128
https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.46
https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.13

Статус уязвимости

Подтверждена производителем

Наличие эксплойта

Данные уточняются

Информация об устранении

Уязвимость устранена

Идентификаторы других систем описаний уязвимостей

EPSS

Процентиль: 4%
0.00018
Низкий

6.6 Medium

CVSS3

6.2 Medium

CVSS2

Связанные уязвимости

CVSS3: 6.6
ubuntu
больше 1 года назад

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Immediately reset the MMU context when the SMM flag is cleared Immediately reset the MMU context when the vCPU's SMM flag is cleared so that the SMM flag in the MMU role is always synchronized with the vCPU's flag. If RSM fails (which isn't correctly emulated), KVM will bail without calling post_leave_smm() and leave the MMU in a bad state. The bad MMU role can lead to a NULL pointer dereference when grabbing a shadow page's rmap for a page fault as the initial lookups for the gfn will happen with the vCPU's SMM flag (=0), whereas the rmap lookup will use the shadow page's SMM flag, which comes from the MMU (=1). SMM has an entirely different set of memslots, and so the initial lookup can find a memslot (SMM=0) and then explode on the rmap memslot lookup (SMM=1). general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x...

CVSS3: 5.5
redhat
больше 1 года назад

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Immediately reset the MMU context when the SMM flag is cleared Immediately reset the MMU context when the vCPU's SMM flag is cleared so that the SMM flag in the MMU role is always synchronized with the vCPU's flag. If RSM fails (which isn't correctly emulated), KVM will bail without calling post_leave_smm() and leave the MMU in a bad state. The bad MMU role can lead to a NULL pointer dereference when grabbing a shadow page's rmap for a page fault as the initial lookups for the gfn will happen with the vCPU's SMM flag (=0), whereas the rmap lookup will use the shadow page's SMM flag, which comes from the MMU (=1). SMM has an entirely different set of memslots, and so the initial lookup can find a memslot (SMM=0) and then explode on the rmap memslot lookup (SMM=1). general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x...

CVSS3: 6.6
nvd
больше 1 года назад

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Immediately reset the MMU context when the SMM flag is cleared Immediately reset the MMU context when the vCPU's SMM flag is cleared so that the SMM flag in the MMU role is always synchronized with the vCPU's flag. If RSM fails (which isn't correctly emulated), KVM will bail without calling post_leave_smm() and leave the MMU in a bad state. The bad MMU role can lead to a NULL pointer dereference when grabbing a shadow page's rmap for a page fault as the initial lookups for the gfn will happen with the vCPU's SMM flag (=0), whereas the rmap lookup will use the shadow page's SMM flag, which comes from the MMU (=1). SMM has an entirely different set of memslots, and so the initial lookup can find a memslot (SMM=0) and then explode on the rmap memslot lookup (SMM=1). general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in rang

CVSS3: 6.6
debian
больше 1 года назад

In the Linux kernel, the following vulnerability has been resolved: K ...

CVSS3: 6.6
github
больше 1 года назад

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Immediately reset the MMU context when the SMM flag is cleared Immediately reset the MMU context when the vCPU's SMM flag is cleared so that the SMM flag in the MMU role is always synchronized with the vCPU's flag. If RSM fails (which isn't correctly emulated), KVM will bail without calling post_leave_smm() and leave the MMU in a bad state. The bad MMU role can lead to a NULL pointer dereference when grabbing a shadow page's rmap for a page fault as the initial lookups for the gfn will happen with the vCPU's SMM flag (=0), whereas the rmap lookup will use the shadow page's SMM flag, which comes from the MMU (=1). SMM has an entirely different set of memslots, and so the initial lookup can find a memslot (SMM=0) and then explode on the rmap memslot lookup (SMM=1). general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in r...

EPSS

Процентиль: 4%
0.00018
Низкий

6.6 Medium

CVSS3

6.2 Medium

CVSS2