CVE-2021-28691
https://notcve.org/view.php?id=CVE-2021-28691
Guest triggered use-after-free in Linux xen-netback A malicious or buggy network PV frontend can force Linux netback to disable the interface and terminate the receive kernel thread associated with queue 0 in response to the frontend sending a malformed packet. Such kernel thread termination will lead to a use-after-free in Linux netback when the backend is destroyed, as the kernel thread associated with queue 0 will have already exited and thus the call to kthread_stop will be performed against a stale pointer. Un uso de memoria previamente liberada desencadenado por el usuario en Linux xen-netback. Un frontend de red PV malicioso o con errores puede forzar a Linux netback a deshabilitar la interfaz y terminar el hilo del kernel de recepción asociado a la cola 0 en respuesta al envío de un paquete malformado por parte del frontend. Esta terminación del hilo del kernel conllevará un uso de memoria previamente liberada en Linux netback cuando es destruído el backend, ya que el hilo del kernel asociado a la cola 0 ya habrá salido y, por tanto, la llamada a la función kthread_stop se llevará a cabo contra un puntero obsoleto • https://security.gentoo.org/glsa/202107-30 https://security.netapp.com/advisory/ntap-20210805-0002 https://xenbits.xenproject.org/xsa/advisory-374.txt • CWE-416: Use After Free •
CVE-2020-28097
https://notcve.org/view.php?id=CVE-2020-28097
The vgacon subsystem in the Linux kernel before 5.8.10 mishandles software scrollback. There is a vgacon_scrolldelta out-of-bounds read, aka CID-973c096f6a85. El subsistema vgacon en el kernel de Linux versiones anteriores a 5.8.10, maneja inapropiadamente el desplazamiento de software. Se presenta una lectura fuera de límites en la función vgacon_scrolldelta, también se conoce como CID-973c096f6a85 • https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.8.10 https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=973c096f6a85e5b5f2a295126ba6928d9a6afd45 https://github.com/torvalds/linux/commit/973c096f6a85e5b5f2a295126ba6928d9a6afd45 https://seclists.org/oss-sec/2020/q3/176 https://security.netapp.com/advisory/ntap-20210805-0001 • CWE-125: Out-of-bounds Read •
CVE-2021-3600 – kernel: eBPF 32-bit source register truncation on div/mod
https://notcve.org/view.php?id=CVE-2021-3600
It was discovered that the eBPF implementation in the Linux kernel did not properly track bounds information for 32 bit registers when performing div and mod operations. A local attacker could use this to possibly execute arbitrary code. Se descubrió que la implementación de eBPF en el kernel de Linux no rastreaba adecuadamente la información de límites para registros de 32 bits al realizar operaciones div y mod. Un atacante local podría usar esto para posiblemente ejecutar código arbitrario. A flaw was found in the Linux kernel’s eBPF verification code, where the eBPF 32-bit div/mod source register truncation could lead to out-of-bounds reads and writes. • https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3600 https://git.kernel.org/linus/e88b2c6e5a4d9ce30d75391e4d950da74bb2bd90 https://ubuntu.com/security/notices/USN-5003-1 https://access.redhat.com/security/cve/CVE-2021-3600 https://bugzilla.redhat.com/show_bug.cgi?id=1981954 • CWE-125: Out-of-bounds Read CWE-787: Out-of-bounds Write •
CVE-2021-33624
https://notcve.org/view.php?id=CVE-2021-33624
In kernel/bpf/verifier.c in the Linux kernel before 5.12.13, a branch can be mispredicted (e.g., because of type confusion) and consequently an unprivileged BPF program can read arbitrary memory locations via a side-channel attack, aka CID-9183671af6db. En el archivo kernel/bpf/verifier.c en el kernel de Linux versiones anteriores a 5.12.13, una rama puede ser mal predicha (por ejemplo, debido a la confusión de tipos) y, en consecuencia, un programa BPF no privilegiado puede leer ubicaciones de memoria arbitrarias por medio de un ataque de canal lateral, también conocido como CID-9183671af6db • https://github.com/benschlueter/CVE-2021-33624 http://www.openwall.com/lists/oss-security/2021/06/21/1 https://github.com/torvalds/linux/commit/9183671af6dbf60a1219371d4ed73e23f43b49db https://lists.debian.org/debian-lts-announce/2021/10/msg00010.html https://www.usenix.org/conference/usenixsecurity21/presentation/kirzner • CWE-843: Access of Resource Using Incompatible Type ('Type Confusion') •
CVE-2021-3609 – kernel: race condition in net/can/bcm.c leads to local privilege escalation
https://notcve.org/view.php?id=CVE-2021-3609
.A flaw was found in the CAN BCM networking protocol in the Linux kernel, where a local attacker can abuse a flaw in the CAN subsystem to corrupt memory, crash the system or escalate privileges. This race condition in net/can/bcm.c in the Linux kernel allows for local privilege escalation to root. Se ha encontrado un fallo en el protocolo de red CAN BCM en el kernel de Linux, donde un atacante local puede abusar de un fallo en el subsistema CAN para corromper la memoria, bloquear el sistema o escalar privilegios. Esta condición de carrera en el archivo net/can/bcm.c en el kernel de Linux permite una escalada de privilegios local a root A flaw was found in the CAN BCM networking protocol in the Linux kernel, where a local attacker can abuse a flaw in the CAN subsystem to corrupt memory, crash the system or escalate privileges. • https://bugzilla.redhat.com/show_bug.cgi?id=1971651 https://github.com/nrb547/kernel-exploitation/blob/main/cve-2021-3609/cve-2021-3609.md https://github.com/torvalds/linux/commit/d5f9023fa61ee8b94f37a93f08e94b136cf1e463 https://security.netapp.com/advisory/ntap-20220419-0004 https://www.openwall.com/lists/oss-security/2021/06/19/1 https://access.redhat.com/security/cve/CVE-2021-3609 • CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') •