CVE-2020-25212 – kernel: TOCTOU mismatch in the NFS client code
https://notcve.org/view.php?id=CVE-2020-25212
A TOCTOU mismatch in the NFS client code in the Linux kernel before 5.8.3 could be used by local attackers to corrupt memory or possibly have unspecified other impact because a size check is in fs/nfs/nfs4proc.c instead of fs/nfs/nfs4xdr.c, aka CID-b4487b935452. Una discrepancia de TOCTOU en el código del cliente NFS en el kernel de Linux versiones anteriores a 5.8.3, podría ser usada por atacantes locales para dañar la memoria o posiblemente tener otro impacto no especificado porque una comprobación de tamaño se encuentra en el archivo fs/nfs/nfs4proc.c en lugar de fs/nfs/nfs4xdr.c, también se conoce como CID-b4487b935452. A flaw was found in the NFSv4 implementation where when mounting a remote attacker controlled server it could return specially crafted response allow for local memory corruption and possibly privilege escalation. • http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00021.html http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00035.html http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00042.html https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.8.3 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b4487b93545214a9db8cbf32e86411677b0cca21 https://lists.debian.org/debian-lts-announce/2020/09/msg00025.html https://lists.debian.org • CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition CWE-787: Out-of-bounds Write •
CVE-2020-25211 – kernel: Local buffer overflow in ctnetlink_parse_tuple_filter in net/netfilter/nf_conntrack_netlink.c
https://notcve.org/view.php?id=CVE-2020-25211
In the Linux kernel through 5.8.7, local attackers able to inject conntrack netlink configuration could overflow a local buffer, causing crashes or triggering use of incorrect protocol numbers in ctnetlink_parse_tuple_filter in net/netfilter/nf_conntrack_netlink.c, aka CID-1cc5ef91d2ff. En el kernel de Linux versiones hasta 5.8.7, los atacantes locales capaces de inyectar la configuración netlink de conntrack podrían desbordar un búfer local, causando bloqueos o desencadenando el uso de números de protocolo incorrectos en la función ctnetlink_parse_tuple_filter en el archivo net/netfilter/nf_conntrack_netlink.c, también se conoce como CID-1cc5ef91d2ff. A flaw was found in the Linux kernel. A local attacker, able to inject conntrack netlink configuration, could overflow a local buffer causing crashes or triggering the use of incorrect protocol numbers in ctnetlink_parse_tuple_filter in net/netfilter/nf_conntrack_netlink.c. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability. • https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1cc5ef91d2ff94d2bf2de3b3585423e8a1051cb6 https://lists.debian.org/debian-lts-announce/2020/10/msg00028.html https://lists.debian.org/debian-lts-announce/2020/10/msg00032.html https://lists.debian.org/debian-lts-announce/2020/10/msg00034.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BL2O4JAMPJG4YMLLJ7JFDHDJRXN4RKTC https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedora • CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') •
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-2020-24394 – kernel: umask not applied on filesystem without ACL support
https://notcve.org/view.php?id=CVE-2020-24394
In the Linux kernel before 5.7.8, fs/nfsd/vfs.c (in the NFS server) can set incorrect permissions on new filesystem objects when the filesystem lacks ACL support, aka CID-22cf8419f131. This occurs because the current umask is not considered. En el kernel de Linux versiones anteriores a 5.7.8, el archivo fs/nfsd/vfs.c (en el servidor NFS), puede establecer permisos incorrectos en nuevos objetos de un sistema de archivos cuando el sistema de archivos carece de soporte de ACL, también se conoce como CID-22cf8419f131. Esto ocurre porque no es considerada la umask actual. A vulnerability was found in NFSv4.2 in the Linux kernel, where a server fails to correctly apply umask when creating a new object on filesystem without ACL support (for example, ext4 with the "noacl" mount option). • http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00007.html https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=962254 https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.7.8 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=22cf8419f1319ff87ec759d0ebdff4cbafaee832 https://security.netapp.com/advisory/ntap-20200904-0003 https://usn.ubuntu.com/4465-1 https://usn.ubuntu.com/4483-1 https://usn.ubuntu.com/4485-1 https://www.orac • CWE-732: Incorrect Permission Assignment for Critical Resource •
CVE-2020-16166 – kernel: information exposure in drivers/char/random.c and kernel/time/timer.c
https://notcve.org/view.php?id=CVE-2020-16166
The Linux kernel through 5.7.11 allows remote attackers to make observations that help to obtain sensitive information about the internal state of the network RNG, aka CID-f227e3ec3b5c. This is related to drivers/char/random.c and kernel/time/timer.c. El kernel de Linux versiones hasta 5.7.11, permite a atacantes remotos realizar observaciones que ayudan a obtener información confidencial sobre el estado interno de la red RNG, también se conoce como CID-f227e3ec3b5c. Esto está relacionado con los archivos drivers/char/random.c y kernel/time/timer.c A flaw was found in the Linux kernel. The generation of the device ID from the network RNG internal state is predictable. • http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00009.html http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00047.html https://arxiv.org/pdf/2012.07432.pdf https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=f227e3ec3b5cad859ad15666874405e8c1bbc1d4 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c51f8f88d705e06bd696d7510aff22b33eb8e638 https://github.com/torvalds/linux/commit/f227e3ec3b5cad859ad15666874405e8c1bbc1d4 https://lists.debian& • CWE-200: Exposure of Sensitive Information to an Unauthorized Actor CWE-330: Use of Insufficiently Random Values •