Описание
arch/x86/kernel/tls.c in the Thread Local Storage (TLS) implementation in the Linux kernel through 3.18.1 allows local users to bypass the espfix protection mechanism, and consequently makes it easier for local users to bypass the ASLR protection mechanism, via a crafted application that makes a set_thread_area system call and later reads a 16-bit value.
It was found that the espfix functionality could be bypassed by installing a 16-bit RW data segment into GDT instead of LDT (which espfix checks), and using that segment on the stack. A local, unprivileged user could potentially use this flaw to leak kernel stack addresses.
Отчет
This issue did not affect the Linux kernel packages as shipped with Red Hat Enterprise Linux 7 and Red Hat Enterprise Linux MRG 2. Red Hat Enterprise Linux 5 is now in Production 3 Phase of the support and maintenance life cycle. This has been rated as having Low security impact and is not currently planned to be addressed in future updates. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 5 | kernel | Will not fix | ||
| Red Hat Enterprise Linux 7 | kernel | Not affected | ||
| Red Hat Enterprise MRG 2 | kernel | Not affected | ||
| Red Hat Enterprise Linux 6 | kernel | Fixed | RHSA-2015:1272 | 20.07.2015 |
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Дополнительная информация
Статус:
EPSS
1.9 Low
CVSS2
Связанные уязвимости
arch/x86/kernel/tls.c in the Thread Local Storage (TLS) implementation in the Linux kernel through 3.18.1 allows local users to bypass the espfix protection mechanism, and consequently makes it easier for local users to bypass the ASLR protection mechanism, via a crafted application that makes a set_thread_area system call and later reads a 16-bit value.
arch/x86/kernel/tls.c in the Thread Local Storage (TLS) implementation in the Linux kernel through 3.18.1 allows local users to bypass the espfix protection mechanism, and consequently makes it easier for local users to bypass the ASLR protection mechanism, via a crafted application that makes a set_thread_area system call and later reads a 16-bit value.
arch/x86/kernel/tls.c in the Thread Local Storage (TLS) implementation ...
arch/x86/kernel/tls.c in the Thread Local Storage (TLS) implementation in the Linux kernel through 3.18.1 allows local users to bypass the espfix protection mechanism, and consequently makes it easier for local users to bypass the ASLR protection mechanism, via a crafted application that makes a set_thread_area system call and later reads a 16-bit value.
ELSA-2015-3055: Unbreakable Enterprise kernel security update (MODERATE)
EPSS
1.9 Low
CVSS2