CVE-2020-10781
https://notcve.org/view.php?id=CVE-2020-10781
A flaw was found in the Linux Kernel before 5.8-rc6 in the ZRAM kernel module, where a user with a local account and the ability to read the /sys/class/zram-control/hot_add file can create ZRAM device nodes in the /dev/ directory. This read allocates kernel memory and is not accounted for a user that triggers the creation of that ZRAM device. With this vulnerability, continually reading the device may consume a large amount of system memory and cause the Out-of-Memory (OOM) killer to activate and terminate random userspace processes, possibly making the system inoperable. Se encontró un fallo en el kernel de Linux versiones anteriores a 5.8-rc6 en el módulo del kernel ZRAM, donde un usuario con una cuenta local y la capacidad de leer el archivo /sys/class/zram-control/hot_add puede crear nodos de dispositivo ZRAM en el directorio /dev/. Esta lectura asigna memoria del kernel y no es contabilizada para un usuario que activa la creación de ese dispositivo ZRAM. • https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-10781 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=853eab68afc80f59f36bbdeb715e5c88c501e680 https://lists.debian.org/debian-lts-announce/2020/09/msg00025.html https://www.openwall.com/lists/oss-security/2020/06/18/1 • CWE-732: Incorrect Permission Assignment for Critical Resource •
CVE-2020-10766 – kernel: Rogue cross-process SSBD shutdown. Linux scheduler logical bug allows an attacker to turn off the SSBD protection.
https://notcve.org/view.php?id=CVE-2020-10766
A logic bug flaw was found in Linux kernel before 5.8-rc1 in the implementation of SSBD. A bug in the logic handling allows an attacker with a local account to disable SSBD protection during a context switch when additional speculative execution mitigations are in place. This issue was introduced when the per task/process conditional STIPB switching was added on top of the existing SSBD switching. The highest threat from this vulnerability is to confidentiality. Se encontró un fallo de bug lógico en el kernel de Linux versiones anteriores a 5.8-rc1, en la implementación de SSBD. • https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-10766 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=dbbe2ad02e9df26e372f38cc3e70dab9222c832e https://access.redhat.com/security/cve/CVE-2020-10766 https://bugzilla.redhat.com/show_bug.cgi?id=1845840 • CWE-440: Expected Behavior Violation •
CVE-2020-10768 – kernel: Indirect branch speculation can be enabled after it was force-disabled by the PR_SPEC_FORCE_DISABLE prctl command.
https://notcve.org/view.php?id=CVE-2020-10768
A flaw was found in the Linux Kernel before 5.8-rc1 in the prctl() function, where it can be used to enable indirect branch speculation after it has been disabled. This call incorrectly reports it as being 'force disabled' when it is not and opens the system to Spectre v2 attacks. The highest threat from this vulnerability is to confidentiality. Se encontró un fallo en el kernel de Linux versiones anteriores a 5.8-rc1 en la función prctl(), donde puede ser usado para habilitar la especulación de rama indirecta después de haber sido deshabilitada. Esta llamada reporta incorrectamente que está "force disabled" cuando no lo está y abre el sistema a ataques de Spectre v2. • https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-10768 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=4d8df8cbb9156b0a0ab3f802b80cb5db57acc0bf https://access.redhat.com/security/cve/CVE-2020-10768 https://bugzilla.redhat.com/show_bug.cgi?id=1845868 • CWE-440: Expected Behavior Violation •
CVE-2020-10767 – kernel: Indirect Branch Prediction Barrier is force-disabled when STIBP is unavailable or enhanced IBRS is available.
https://notcve.org/view.php?id=CVE-2020-10767
A flaw was found in the Linux kernel before 5.8-rc1 in the implementation of the Enhanced IBPB (Indirect Branch Prediction Barrier). The IBPB mitigation will be disabled when STIBP is not available or when the Enhanced Indirect Branch Restricted Speculation (IBRS) is available. This flaw allows a local attacker to perform a Spectre V2 style attack when this configuration is active. The highest threat from this vulnerability is to confidentiality. Se encontró un fallo en el kernel de Linux versiones anteriores a 5.8-rc1, en la implementación de la Enhanced IBPB (Indirect Branch Prediction Barrier). • https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-10767 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=21998a351512eba4ed5969006f0c55882d995ada https://access.redhat.com/security/cve/CVE-2020-10767 https://bugzilla.redhat.com/show_bug.cgi?id=1845867 • CWE-440: Expected Behavior Violation •
CVE-2019-19448
https://notcve.org/view.php?id=CVE-2019-19448
In the Linux kernel 5.0.21 and 5.3.11, mounting a crafted btrfs filesystem image, performing some operations, and then making a syncfs system call can lead to a use-after-free in try_merge_free_space in fs/btrfs/free-space-cache.c because the pointer to a left data structure can be the same as the pointer to a right data structure. En el kernel de Linux versiones 5.0.21 y 5.3.11, montando una imagen de sistema de archivos btrfs diseñada, al realizar algunas operaciones y luego haciendo una llamada de sistema syncfs puede conllevar a un uso de la memoria previamente liberada en la función try_merge_free_space en el archivo fs/btrfs/free-space-cache.c porque el puntero en una estructura de datos izquierda puede ser el mismo que el puntero en una estructura de datos derecha. • https://github.com/bobfuzzer/CVE/tree/master/CVE-2019-19448 https://lists.debian.org/debian-lts-announce/2020/09/msg00025.html https://lists.debian.org/debian-lts-announce/2020/10/msg00032.html https://lists.debian.org/debian-lts-announce/2020/10/msg00034.html https://security.netapp.com/advisory/ntap-20200103-0001 https://usn.ubuntu.com/4578-1 • CWE-416: Use After Free •