Memory corruption in Linux kernel - CVE-2021-20239

Vulnerability identifier: #VU92759

CSH Severity: Low

CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2021-20239

CWE-ID: CWE-119

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to gain access to sensitive information.

A flaw was found in the Linux kernel in versions before 5.4.92 in the BPF protocol. This flaw allows an attacker with a local account to leak information about kernel internal addresses. The highest threat from this vulnerability is to confidentiality.

Linux kernel
Red Hat Enterprise Linux for Real Time
Red Hat Enterprise Linux for Real Time for NFV
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for ARM 64
Red Hat CodeReady Linux Builder for x86_64
Red Hat CodeReady Linux Builder for Power, little endian
Red Hat CodeReady Linux Builder for ARM 64
Ubuntu
kernel (Red Hat package)
kernel-rt (Red Hat package)
linux-image-virtual (Ubuntu package)
linux-image-oem-osp1 (Ubuntu package)
linux-image-oem (Ubuntu package)
linux-image-lowlatency (Ubuntu package)
linux-image-generic-lpae (Ubuntu package)
linux-image-generic (Ubuntu package)
linux-image-5.4.0-67-generic (Ubuntu package)
linux-image-5.4.0-67-generic-lpae (Ubuntu package)
linux-image-5.4.0-67-lowlatency (Ubuntu package)
linux-image-virtual-hwe-18.04 (Ubuntu package)
linux-image-snapdragon-hwe-18.04 (Ubuntu package)
linux-image-lowlatency-hwe-18.04 (Ubuntu package)
linux-image-generic-hwe-18.04 (Ubuntu package)
linux-image-generic-lpae-hwe-18.04 (Ubuntu package)
linux-image-5.4.0-1011-gkeop (Ubuntu package)
linux-image-gkeop-5.4 (Ubuntu package)
linux-image-gkeop (Ubuntu package)
linux-image-raspi-hwe-18.04 (Ubuntu package)
linux-image-5.4.0-1030-raspi (Ubuntu package)
linux-image-raspi2 (Ubuntu package)
linux-image-raspi (Ubuntu package)
linux-image-kvm (Ubuntu package)
linux-image-5.4.0-1034-kvm (Ubuntu package)
linux-image-5.4.0-1037-gke (Ubuntu package)
linux-image-gke-5.4 (Ubuntu package)
linux-image-gcp (Ubuntu package)
linux-image-gcp-edge (Ubuntu package)
linux-image-5.4.0-1038-gcp (Ubuntu package)
linux-image-aws (Ubuntu package)
linux-image-aws-edge (Ubuntu package)
linux-image-oracle (Ubuntu package)
linux-image-5.4.0-1039-aws (Ubuntu package)
linux-image-5.4.0-1039-oracle (Ubuntu package)
linux-image-azure (Ubuntu package)
linux-image-azure-edge (Ubuntu package)
linux-image-5.4.0-1041-azure (Ubuntu package)
linux-image-oem-20.04 (Ubuntu package)
linux-image-generic-64k (Ubuntu package)
linux-image-5.8.0-49-lowlatency (Ubuntu package)
linux-image-5.8.0-49-generic-lpae (Ubuntu package)
linux-image-5.8.0-49-generic (Ubuntu package)
linux-image-5.8.0-49-generic-64k (Ubuntu package)
linux-image-virtual-hwe-20.04 (Ubuntu package)
linux-image-lowlatency-hwe-20.04 (Ubuntu package)
linux-image-generic-lpae-hwe-20.04 (Ubuntu package)
linux-image-generic-hwe-20.04 (Ubuntu package)
linux-image-generic-64k-hwe-20.04 (Ubuntu package)
linux-image-5.8.0-1020-raspi-nolpae (Ubuntu package)
linux-image-raspi-nolpae (Ubuntu package)
linux-image-5.8.0-1020-raspi (Ubuntu package)
linux-image-5.8.0-1023-kvm (Ubuntu package)
linux-image-5.8.0-1025-oracle (Ubuntu package)
linux-image-gke (Ubuntu package)
linux-image-5.8.0-1027-gcp (Ubuntu package)
linux-image-5.8.0-1027-azure (Ubuntu package)
linux-image-5.8.0-1028-aws (Ubuntu package)

Install update from vendor's repository.

kernel (Red Hat package) - update to 4.18.0-348.el8
kernel-rt (Red Hat package) - update to 4.18.0-348.rt7.130.el8
linux-image-virtual (Ubuntu package) - addressed in versions 5.4.0.67.70, 5.8.0.49.54
linux-image-oem-osp1 (Ubuntu package) - addressed in versions 5.4.0.67.70, 5.4.0.67.75~18.04.62
linux-image-oem (Ubuntu package) - addressed in versions 5.4.0.67.70, 5.4.0.67.75~18.04.62
linux-image-lowlatency (Ubuntu package) - addressed in versions 5.4.0.67.70, 5.8.0.49.54
linux-image-generic-lpae (Ubuntu package) - addressed in versions 5.4.0.67.70, 5.8.0.49.54
linux-image-generic (Ubuntu package) - addressed in versions 5.4.0.67.70, 5.8.0.49.54
linux-image-5.4.0-67-generic (Ubuntu package) - addressed in versions 5.4.0-67.75, 5.4.0-67.75~18.04.1
linux-image-5.4.0-67-generic-lpae (Ubuntu package) - addressed in versions 5.4.0-67.75, 5.4.0-67.75~18.04.1
linux-image-5.4.0-67-lowlatency (Ubuntu package) - addressed in versions 5.4.0-67.75, 5.4.0-67.75~18.04.1
linux-image-virtual-hwe-18.04 (Ubuntu package) - update to 5.4.0.67.75~18.04.62
linux-image-snapdragon-hwe-18.04 (Ubuntu package) - update to 5.4.0.67.75~18.04.62
linux-image-lowlatency-hwe-18.04 (Ubuntu package) - update to 5.4.0.67.75~18.04.62
linux-image-generic-hwe-18.04 (Ubuntu package) - update to 5.4.0.67.75~18.04.62
linux-image-generic-lpae-hwe-18.04 (Ubuntu package) - update to 5.4.0.67.75~18.04.62
linux-image-5.4.0-1011-gkeop (Ubuntu package) - addressed in versions 5.4.0-1011.12, 5.4.0-1011.12~18.04.2
linux-image-gkeop-5.4 (Ubuntu package) - addressed in versions 5.4.0.1011.12~18.04.12, 5.4.0.1011.14
linux-image-gkeop (Ubuntu package) - update to 5.4.0.1011.14
linux-image-raspi-hwe-18.04 (Ubuntu package) - update to 5.4.0.1030.33
linux-image-5.4.0-1030-raspi (Ubuntu package) - addressed in versions 5.4.0-1030.33, 5.4.0-1030.33~18.04.1
linux-image-raspi2 (Ubuntu package) - update to 5.4.0.1030.65
linux-image-raspi (Ubuntu package) - addressed in versions 5.4.0.1030.65, 5.8.0.1020.23
linux-image-kvm (Ubuntu package) - addressed in versions 5.4.0.1034.32, 5.8.0.1023.25
linux-image-5.4.0-1034-kvm (Ubuntu package) - update to 5.4.0-1034.35
linux-image-5.4.0-1037-gke (Ubuntu package) - update to 5.4.0-1037.39~18.04.1
linux-image-gke-5.4 (Ubuntu package) - update to 5.4.0.1037.39~18.04.5
linux-image-gcp (Ubuntu package) - addressed in versions 5.4.0.1038.25, 5.4.0.1038.47, 5.8.0.1027.27
linux-image-gcp-edge (Ubuntu package) - update to 5.4.0.1038.25
linux-image-5.4.0-1038-gcp (Ubuntu package) - addressed in versions 5.4.0-1038.41, 5.4.0-1038.41~18.04.1
linux-image-aws (Ubuntu package) - addressed in versions 5.4.0.1039.23, 5.4.0.1039.40, 5.8.0.1028.30
linux-image-aws-edge (Ubuntu package) - update to 5.4.0.1039.23
linux-image-oracle (Ubuntu package) - addressed in versions 5.4.0.1039.36, 5.4.0.1039.42~18.04.22, 5.8.0.1025.24
linux-image-5.4.0-1039-aws (Ubuntu package) - addressed in versions 5.4.0-1039.41, 5.4.0-1039.41~18.04.1
linux-image-5.4.0-1039-oracle (Ubuntu package) - addressed in versions 5.4.0-1039.42, 5.4.0-1039.42~18.04.1
linux-image-azure (Ubuntu package) - addressed in versions 5.4.0.1041.21, 5.4.0.1041.39, 5.8.0.1027.27
linux-image-azure-edge (Ubuntu package) - update to 5.4.0.1041.21
linux-image-5.4.0-1041-azure (Ubuntu package) - addressed in versions 5.4.0-1041.43, 5.4.0-1041.43~18.04.1
linux-image-oem-20.04 (Ubuntu package) - update to 5.8.0.49.54
linux-image-generic-64k (Ubuntu package) - update to 5.8.0.49.54
linux-image-5.8.0-49-lowlatency (Ubuntu package) - update to 5.8.0-49.55~20.04.1
linux-image-5.8.0-49-generic-lpae (Ubuntu package) - update to 5.8.0-49.55~20.04.1
linux-image-5.8.0-49-generic (Ubuntu package) - update to 5.8.0-49.55~20.04.1
linux-image-5.8.0-49-generic-64k (Ubuntu package) - update to 5.8.0-49.55~20.04.1
linux-image-virtual-hwe-20.04 (Ubuntu package) - update to 5.8.0.49.55~20.04.33
linux-image-lowlatency-hwe-20.04 (Ubuntu package) - update to 5.8.0.49.55~20.04.33
linux-image-generic-lpae-hwe-20.04 (Ubuntu package) - update to 5.8.0.49.55~20.04.33
linux-image-generic-hwe-20.04 (Ubuntu package) - update to 5.8.0.49.55~20.04.33
linux-image-generic-64k-hwe-20.04 (Ubuntu package) - update to 5.8.0.49.55~20.04.33
linux-image-5.8.0-1020-raspi-nolpae (Ubuntu package) - update to 5.8.0-1020.23
linux-image-raspi-nolpae (Ubuntu package) - update to 5.8.0.1020.23
linux-image-5.8.0-1020-raspi (Ubuntu package) - update to 5.8.0-1020.23
linux-image-5.8.0-1023-kvm (Ubuntu package) - update to 5.8.0-1023.25
linux-image-5.8.0-1025-oracle (Ubuntu package) - update to 5.8.0-1025.26
linux-image-gke (Ubuntu package) - update to 5.8.0.1027.27
linux-image-5.8.0-1027-gcp (Ubuntu package) - update to 5.8.0-1027.28
linux-image-5.8.0-1027-azure (Ubuntu package) - update to 5.8.0-1027.29
linux-image-5.8.0-1028-aws (Ubuntu package) - update to 5.8.0-1028.30

• https://bugzilla.redhat.com/show_bug.cgi?id=1923636

• Memory corruption in Linux kernel
• Red Hat Enterprise Linux 8 update for kernel-rt
• Red Hat Enterprise Linux 8 update for kernel
• Ubuntu update for linux
• Ubuntu update for linux