CVSS: 7.4EPSS: 0%CPEs: 33EXPL: 0CVE-2021-4083 – kernel: fget: check that the fd still exists after getting a ref to it
https://notcve.org/view.php?id=CVE-2021-4083
A read-after-free memory flaw was found in the Linux kernel's garbage collection for Unix domain socket file handlers in the way users call close() and fget() simultaneously and can potentially trigger a race condition. This flaw allows a local user to crash the system or escalate their privileges on the system. This flaw affects Linux kernel versions prior to 5.16-rc4. Se ha encontrado un fallo de lectura de memoria previamente liberada en la recolección de basura del kernel de Linux para los manejadores de archivos de socket de dominio Unix en la forma en que los usuarios llaman a close() y fget() simultáneamente y puede potencialmente desencadenar una condición de carrera. Este fallo permite a un usuario local bloquear el sistema o escalar sus privilegios en el sistema. • https://bugzilla.redhat.com/show_bug.cgi?id=2029923 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=054aa8d439b9 https://lists.debian.org/debian-lts-announce/2022/03/msg00011.html https://lists.debian.org/debian-lts-announce/2022/03/msg00012.html https://security.netapp.com/advisory/ntap-20220217-0005 https://www.debian.org/security/2022/dsa-5096 https://www.oracle.com/security-alerts/cpujul2022.html https://access.redhat.com/security/cve/CVE-202 • CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') CWE-416: Use After Free •
CVSS: 4.7EPSS: 0%CPEs: 2EXPL: 0CVE-2021-4001
https://notcve.org/view.php?id=CVE-2021-4001
A race condition was found in the Linux kernel's ebpf verifier between bpf_map_update_elem and bpf_map_freeze due to a missing lock in kernel/bpf/syscall.c. In this flaw, a local user with a special privilege (cap_sys_admin or cap_bpf) can modify the frozen mapped address space. This flaw affects kernel versions prior to 5.16 rc2. Se ha encontrado una condición de carrera en el verificador ebpf del kernel de Linux entre las funciones bpf_map_update_elem y bpf_map_freeze debido a la falta de un bloqueo en el archivo kernel/bpf/syscall.c. En este fallo, un usuario local con un privilegio especial (cap_sys_admin o cap_bpf) puede modificar el espacio de direcciones mapeado congelado. • https://bugzilla.redhat.com/show_bug.cgi?id=2025645 https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=353050be4c19e102178ccc05988101887c25ae53 • CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition •
CVSS: 5.1EPSS: 0%CPEs: 10EXPL: 1CVE-2021-4002 – kernel: possible leak or coruption of data residing on hugetlbfs
https://notcve.org/view.php?id=CVE-2021-4002
A memory leak flaw in the Linux kernel's hugetlbfs memory usage was found in the way the user maps some regions of memory twice using shmget() which are aligned to PUD alignment with the fault of some of the memory pages. A local user could use this flaw to get unauthorized access to some data. Se encontró un fallo de pérdida de memoria en el uso de memoria hugetlbfs del kernel de Linux en la forma en que el usuario mapea algunas regiones de memoria dos veces usando shmget() que están alineadas a la alineación PUD con el fallo de algunas de las páginas de memoria. Un usuario local podría usar este fallo para conseguir acceso no autorizado a algunos datos • https://bugzilla.redhat.com/show_bug.cgi?id=2025726 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=13e4ad2ce8df6e058ef482a31fdd81c725b0f7ea https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a4a118f2eead1d6c49e00765de89878288d4b890 https://lists.debian.org/debian-lts-announce/2022/03/msg00011.html https://lists.debian.org/debian-lts-announce/2022/03/msg00012.html https://www.debian.org/security/2022/dsa-5096 https://www.openwall.com/list • CWE-401: Missing Release of Memory after Effective Lifetime CWE-459: Incomplete Cleanup •
CVSS: 6.5EPSS: 0%CPEs: 4EXPL: 0CVE-2021-28715
https://notcve.org/view.php?id=CVE-2021-28715
Guest can force Linux netback driver to hog large amounts of kernel memory T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Incoming data packets for a guest in the Linux kernel's netback driver are buffered until the guest is ready to process them. There are some measures taken for avoiding to pile up too much data, but those can be bypassed by the guest: There is a timeout how long the client side of an interface can stop consuming new packets before it is assumed to have stalled, but this timeout is rather long (60 seconds by default). Using a UDP connection on a fast interface can easily accumulate gigabytes of data in that time. (CVE-2021-28715) The timeout could even never trigger if the guest manages to have only one free slot in its RX queue ring page and the next package would require more than one free slot, which may be the case when using GSO, XDP, or software hashing. • https://lists.debian.org/debian-lts-announce/2022/03/msg00011.html https://lists.debian.org/debian-lts-announce/2022/03/msg00012.html https://www.debian.org/security/2022/dsa-5050 https://www.debian.org/security/2022/dsa-5096 https://xenbits.xenproject.org/xsa/advisory-392.txt • CWE-770: Allocation of Resources Without Limits or Throttling •
CVSS: 6.5EPSS: 0%CPEs: 3EXPL: 0CVE-2021-28714
https://notcve.org/view.php?id=CVE-2021-28714
Guest can force Linux netback driver to hog large amounts of kernel memory T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Incoming data packets for a guest in the Linux kernel's netback driver are buffered until the guest is ready to process them. There are some measures taken for avoiding to pile up too much data, but those can be bypassed by the guest: There is a timeout how long the client side of an interface can stop consuming new packets before it is assumed to have stalled, but this timeout is rather long (60 seconds by default). Using a UDP connection on a fast interface can easily accumulate gigabytes of data in that time. (CVE-2021-28715) The timeout could even never trigger if the guest manages to have only one free slot in its RX queue ring page and the next package would require more than one free slot, which may be the case when using GSO, XDP, or software hashing. • https://lists.debian.org/debian-lts-announce/2022/03/msg00011.html https://lists.debian.org/debian-lts-announce/2022/03/msg00012.html https://www.debian.org/security/2022/dsa-5050 https://www.debian.org/security/2022/dsa-5096 https://xenbits.xenproject.org/xsa/advisory-392.txt • CWE-770: Allocation of Resources Without Limits or Throttling •