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CVE-2020-28974

Опубликовано: 09 нояб. 2020
Источник: redhat
CVSS3: 5

Описание

A slab-out-of-bounds read in fbcon in the Linux kernel before 5.9.7 could be used by local attackers to read privileged information or potentially crash the kernel, aka CID-3c4e0dff2095. This occurs because KD_FONT_OP_COPY in drivers/tty/vt/vt.c can be used for manipulations such as font height.

An out-of-bounds (OOB) SLAB memory access flaw was found in the Linux kernel's fbcon driver module. A bounds check failure allows a local attacker with special user privileges to gain access to out-of-bounds memory, leading to a system crash or leaking of internal kernel information. The highest threat from this vulnerability is to system availability.

Меры по смягчению последствий

Add 'nomodeset' option as kernel boot parameter to disable frame buffering in /etc/default/grub, and run 'grub2-mkconfig -o /boot/grub2/grub.cfg' and reboot.

# cat /proc/cmdline BOOT_IMAGE=(hd0,msdos1)/vmlinuz-4.18.0-147.el8.x86_64 root=/dev/mapper/rhel_rhel8u2--1-root ro crashkernel=auto resume=/dev/mapper/rhel_rhel8u2--1-swap rd.lvm.lv=rhel_rhel8u2-1/root rd.lvm.lv=rhel_rhel8u2-1/swap nomodeset # ls -l /dev/fb* ls: cannot access '/dev/fb*': No such file or directory

The above said mitigation does not so effect for rhel6 kernel , and is only applicable for rhel7/8.

Затронутые пакеты

ПлатформаПакетСостояниеРекомендацияРелиз
Red Hat Enterprise Linux 5kernelOut of support scope
Red Hat Enterprise Linux 6kernelOut of support scope
Red Hat Enterprise Linux 7kernelWill not fix
Red Hat Enterprise Linux 7kernel-altWill not fix
Red Hat Enterprise Linux 7kernel-rtWill not fix
Red Hat Enterprise MRG 2kernel-rtWill not fix
Red Hat Enterprise Linux 8kernel-rtFixedRHSA-2021:173918.05.2021
Red Hat Enterprise Linux 8kernelFixedRHSA-2021:157818.05.2021

Показывать по

Дополнительная информация

Статус:

Moderate
Дефект:
CWE-125
https://bugzilla.redhat.com/show_bug.cgi?id=1903126kernel: slab-out-of-bounds read in fbcon

5 Medium

CVSS3

Связанные уязвимости

CVSS3: 5
ubuntu
больше 4 лет назад

A slab-out-of-bounds read in fbcon in the Linux kernel before 5.9.7 could be used by local attackers to read privileged information or potentially crash the kernel, aka CID-3c4e0dff2095. This occurs because KD_FONT_OP_COPY in drivers/tty/vt/vt.c can be used for manipulations such as font height.

CVSS3: 5
nvd
больше 4 лет назад

A slab-out-of-bounds read in fbcon in the Linux kernel before 5.9.7 could be used by local attackers to read privileged information or potentially crash the kernel, aka CID-3c4e0dff2095. This occurs because KD_FONT_OP_COPY in drivers/tty/vt/vt.c can be used for manipulations such as font height.

CVSS3: 5
msrc
больше 4 лет назад

Описание отсутствует

CVSS3: 5
debian
больше 4 лет назад

A slab-out-of-bounds read in fbcon in the Linux kernel before 5.9.7 co ...

github
около 3 лет назад

A slab-out-of-bounds read in fbcon in the Linux kernel before 5.9.7 could be used by local attackers to read privileged information or potentially crash the kernel, aka CID-3c4e0dff2095. This occurs because KD_FONT_OP_COPY in drivers/tty/vt/vt.c can be used for manipulations such as font height.

5 Medium

CVSS3