CVE-2021-3715

Description

A flaw was found in the "Routing decision" classifier in the Linux kernel's Traffic Control networking subsystem in the way it handled changing of classification filters, leading to a use-after-free condition. This flaw allows unprivileged local users to escalate their privileges on the system. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.

CVSS Metrics

• v3.1•HIGH•Score: 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
• v2.0•HIGH•Score: 7.2AV:L/AC:L/Au:N/C:C/I:C/A:C

EPSS Trends

Current EPSS score: 0.35%• Percentile: 29%

Techniques & Countermeasures

• CWE-416•Use After Free

  The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Affected Systems

• debian•linux

  < 5.5.17-1 | < 5.5.17-1 | < 5.5.17-1 | < 5.5.17-1

• ubuntu•linux

  < 4.4.0-179.209 | < 4.15.0-99.100

• ubuntu•linux-aws

  < 4.4.0-1067.71 | < 4.4.0-1107.118 | < 4.15.0-1066.70

• ubuntu•linux-aws-5.0

  all

• ubuntu•linux-aws-5.3

  all

• ubuntu•linux-aws-5.8

  all

• ubuntu•linux-aws-fips

  < 4.15.0-2018.18 | all

• ubuntu•linux-aws-hwe

  < 4.15.0-1066.70~16.04.1

• ubuntu•linux-azure

  < 4.15.0-1082.92~14.04.1 | < 4.15.0-1082.92~16.04.1 | all

• ubuntu•linux-azure-5.3

  all

• ubuntu•linux-azure-edge

  all

• ubuntu•linux-azure-fips

  < 4.15.0-2006.7 | all

• ubuntu•linux-bluefield

  all

• ubuntu•linux-fips

  < 4.4.0-1034.39 | all | < 4.15.0-1029.34

• ubuntu•linux-gcp

  < 4.15.0-1061.65 | all

• ubuntu•linux-gcp-5.3

  all

• ubuntu•linux-gcp-5.8

  all

• ubuntu•linux-gcp-edge

  all

• ubuntu•linux-gcp-fips

  all

• ubuntu•linux-gke-4.15

  all

• ubuntu•linux-hwe

  < 4.15.0-99.100~16.04.1 | all

• ubuntu•linux-hwe-edge

  all | all

• ubuntu•linux-intel-iot-realtime

  all

• ubuntu•linux-kvm

  < 4.4.0-1071.78 | < 4.15.0-1059.60

• ubuntu•linux-lts-xenial

  < 4.4.0-179.209~14.04.1

• ubuntu•linux-oem

  all

• ubuntu•linux-oem-5.6

  all

• ubuntu•linux-oem-osp1

  < 5.0.0-1052.57

• ubuntu•linux-oracle

  < 4.15.0-1038.42~16.04.1 | < 4.15.0-1038.42

• ubuntu•linux-oracle-5.0

  all

• ubuntu•linux-oracle-5.3

  all

• ubuntu•linux-oracle-5.8

  all

• ubuntu•linux-raspi-realtime

  all

• ubuntu•linux-raspi2

  < 4.15.0-1061.65 | all

• ubuntu•linux-realtime

  all

• ubuntu•linux-riscv

  all

• ubuntu•linux-riscv-5.8

  all

• ubuntu•linux-snapdragon

  < 4.15.0-1077.84

• linux•linux_kernel

  ≥ 3.18, < 4.4.218 | ≥ 4.5, < 4.9.218 | ≥ 4.10, < 4.14.175 | ≥ 4.15, < 4.19.114 | ≥ 4.20, < 5.4.29 | ≥ 5.5.0, < 5.5.14

• redhat•bpftool

  < 0:3.10.0-1160.42.2.el7 | < 0:3.10.0-1160.42.2.el7 | < 0:3.10.0-1160.42.2.el7

• redhat•bpftool-debuginfo

  < 0:3.10.0-1160.42.2.el7 | < 0:3.10.0-1160.42.2.el7 | < 0:3.10.0-1160.42.2.el7 | < 0:3.10.0-1160.42.2.el7

• redhat•kernel

  < 0:3.10.0-1160.42.2.el7 | < 0:3.10.0-1160.42.2.el7 | < 0:3.10.0-1160.42.2.el7

• redhat•kernel-abi-whitelists

  < 0:3.10.0-1160.42.2.el7 | < 0:3.10.0-1160.42.2.el7 | < 0:3.10.0-1160.42.2.el7

• redhat•kernel-bootwrapper

  < 0:3.10.0-1160.42.2.el7

• redhat•kernel-debug

  < 0:3.10.0-1160.42.2.el7 | < 0:3.10.0-1160.42.2.el7 | < 0:3.10.0-1160.42.2.el7

• redhat•kernel-debug-debuginfo

  < 0:3.10.0-1160.42.2.el7 | < 0:3.10.0-1160.42.2.el7 | < 0:3.10.0-1160.42.2.el7 | < 0:3.10.0-1160.42.2.el7

• redhat•kernel-debug-devel

  < 0:3.10.0-1160.42.2.el7 | < 0:3.10.0-1160.42.2.el7 | < 0:3.10.0-1160.42.2.el7

• redhat•kernel-debuginfo

  < 0:3.10.0-1160.42.2.el7 | < 0:3.10.0-1160.42.2.el7 | < 0:3.10.0-1160.42.2.el7 | < 0:3.10.0-1160.42.2.el7

• redhat•kernel-debuginfo-common-ppc64

  < 0:3.10.0-1160.42.2.el7

• redhat•kernel-debuginfo-common-ppc64le

  < 0:3.10.0-1160.42.2.el7

Showing first 50 affected entries in server-rendered view.

References (16)

• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ef299cc3fa1a9e1288665a9fdc8bff55629fd359
• https://ubuntu.com/security/CVE-2021-3715
• https://www.openwall.com/lists/oss-security/2021/09/07/1
• https://git.kernel.org/linus/ef299cc3fa1a9e1288665a9fdc8bff55629fd359
• https://access.redhat.com/security/cve/CVE-2021-3715
• https://www.cve.org/CVERecord?id=CVE-2021-3715
• https://security-tracker.debian.org/tracker/CVE-2021-3715
• https://access.redhat.com/errata/RHSA-2021:3438
• https://access.redhat.com/security/updates/classification/#moderate
• https://bugzilla.redhat.com/show_bug.cgi?id=1993988
• https://security.access.redhat.com/data/csaf/v2/advisories/2021/rhsa-2021_3438.json
• https://nvd.nist.gov/vuln/detail/CVE-2021-3715
• https://access.redhat.com/errata/RHSA-2021:3439
• https://security.access.redhat.com/data/csaf/v2/advisories/2021/rhsa-2021_3439.json
• https://access.redhat.com/errata/RHSA-2021:3441
• https://security.access.redhat.com/data/csaf/v2/advisories/2021/rhsa-2021_3441.json