Improper Privilege Management in Linux kernel - CVE-2021-26708

Vulnerability identifier: #VU52036

CSH Severity: Low

CVSS v4 BT: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Clear]

CVE-ID: CVE-2021-26708

CWE-ID: CWE-269

Exploitation vector: Local access

Exploit availability: The vulnerability is being exploited in the wild

The vulnerability allows a local user to escalate privileges.

The vulnerability exists due to improper privilege management. Multiple race conditions in the AF_VSOCK implementation are caused by wrong locking in net/vmw_vsock/af_vsock.c. The race conditions were implicitly introduced in the commits that added VSOCK multi-transport support.

Linux kernel
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Real Time for NFV
Red Hat Enterprise Linux for Real Time
Red Hat CodeReady Linux Builder for ARM 64
Red Hat CodeReady Linux Builder for Power, little endian
Red Hat CodeReady Linux Builder for x86_64
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for x86_64
Ubuntu
Red Hat Advanced Cluster Management for Kubernetes
kernel (Red Hat package)
kernel-rt (Red Hat package)
linux-image-oem-20.04 (Ubuntu package)
linux-image-5.6.0-1047-oem (Ubuntu package)
linux-image-lowlatency (Ubuntu package)
linux-image-virtual (Ubuntu package)
linux-image-generic-lpae (Ubuntu package)
linux-image-generic-64k (Ubuntu package)
linux-image-generic (Ubuntu package)
linux-image-5.8.0-43-generic (Ubuntu package)
linux-image-5.8.0-43-generic-64k (Ubuntu package)
linux-image-5.8.0-43-generic-lpae (Ubuntu package)
linux-image-5.8.0-43-lowlatency (Ubuntu package)
linux-image-generic-hwe-20.04 (Ubuntu package)
linux-image-generic-64k-hwe-20.04 (Ubuntu package)
linux-image-generic-lpae-hwe-20.04 (Ubuntu package)
linux-image-lowlatency-hwe-20.04 (Ubuntu package)
linux-image-virtual-hwe-20.04 (Ubuntu package)
linux-image-raspi (Ubuntu package)
linux-image-5.8.0-1015-raspi (Ubuntu package)
linux-image-raspi-nolpae (Ubuntu package)
linux-image-5.8.0-1015-raspi-nolpae (Ubuntu package)
linux-image-kvm (Ubuntu package)
linux-image-5.8.0-1018-kvm (Ubuntu package)
linux-image-oracle (Ubuntu package)
linux-image-5.8.0-1020-oracle (Ubuntu package)
linux-image-gke (Ubuntu package)
linux-image-gcp (Ubuntu package)
linux-image-azure (Ubuntu package)
linux-image-5.8.0-1022-gcp (Ubuntu package)
linux-image-5.8.0-1022-azure (Ubuntu package)
linux-image-aws (Ubuntu package)
linux-image-5.8.0-1023-aws (Ubuntu package)

Install updates from vendor's website.

Linux kernel - update to 5.10.13
Red Hat Advanced Cluster Management for Kubernetes - addressed in versions 2.0.10, 2.1.6, 2.2.2
kernel (Red Hat package) - update to 4.18.0-240.22.1.el8_3
kernel-rt (Red Hat package) - update to 4.18.0-240.22.1.rt7.77.el8_3
linux-image-oem-20.04 (Ubuntu package) - update to 5.6.0.1047.43
linux-image-5.6.0-1047-oem (Ubuntu package) - update to 5.6.0-1047.51
linux-image-lowlatency (Ubuntu package) - update to 5.8.0.43.48
linux-image-virtual (Ubuntu package) - update to 5.8.0.43.48
linux-image-generic-lpae (Ubuntu package) - update to 5.8.0.43.48
linux-image-generic-64k (Ubuntu package) - update to 5.8.0.43.48
linux-image-generic (Ubuntu package) - update to 5.8.0.43.48
linux-image-5.8.0-43-generic (Ubuntu package) - addressed in versions 5.8.0-43.49, 5.8.0-43.49~20.04.1
linux-image-5.8.0-43-generic-64k (Ubuntu package) - update to 5.8.0-43.49
linux-image-5.8.0-43-generic-lpae (Ubuntu package) - addressed in versions 5.8.0-43.49, 5.8.0-43.49~20.04.1
linux-image-5.8.0-43-lowlatency (Ubuntu package) - addressed in versions 5.8.0-43.49, 5.8.0-43.49~20.04.1
linux-image-generic-hwe-20.04 (Ubuntu package) - update to 5.8.0.43.49~20.04.29
linux-image-generic-64k-hwe-20.04 (Ubuntu package) - update to 5.8.0.43.49~20.04.29
linux-image-generic-lpae-hwe-20.04 (Ubuntu package) - update to 5.8.0.43.49~20.04.29
linux-image-lowlatency-hwe-20.04 (Ubuntu package) - update to 5.8.0.43.49~20.04.29
linux-image-virtual-hwe-20.04 (Ubuntu package) - update to 5.8.0.43.49~20.04.29
linux-image-raspi (Ubuntu package) - update to 5.8.0.1015.18
linux-image-5.8.0-1015-raspi (Ubuntu package) - update to 5.8.0-1015.18
linux-image-raspi-nolpae (Ubuntu package) - update to 5.8.0.1015.18
linux-image-5.8.0-1015-raspi-nolpae (Ubuntu package) - update to 5.8.0-1015.18
linux-image-kvm (Ubuntu package) - update to 5.8.0.1018.20
linux-image-5.8.0-1018-kvm (Ubuntu package) - update to 5.8.0-1018.20
linux-image-oracle (Ubuntu package) - update to 5.8.0.1020.19
linux-image-5.8.0-1020-oracle (Ubuntu package) - update to 5.8.0-1020.21
linux-image-gke (Ubuntu package) - update to 5.8.0.1022.22
linux-image-gcp (Ubuntu package) - update to 5.8.0.1022.22
linux-image-azure (Ubuntu package) - update to 5.8.0.1022.22
linux-image-5.8.0-1022-gcp (Ubuntu package) - update to 5.8.0-1022.23
linux-image-5.8.0-1022-azure (Ubuntu package) - update to 5.8.0-1022.24
linux-image-aws (Ubuntu package) - update to 5.8.0.1023.25
linux-image-5.8.0-1023-aws (Ubuntu package) - update to 5.8.0-1023.25

• http://www.openwall.com/lists/oss-security/2021/02/05/6
• http://www.openwall.com/lists/oss-security/2021/04/09/2
• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.13
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c518adafa39f37858697ac9309c6cf1805581446
• https://security.netapp.com/advisory/ntap-20210312-0008/
• https://www.openwall.com/lists/oss-security/2021/02/04/5

• Red Hat Enterprise Linux 8 update for kernel
• Red Hat Enterprise Linux 8 update for kernel-rt
• Multiple vulnerabilities in Red Hat Advanced Cluster Management for Kubernetes
• Multiple vulnerabilities in Red Hat Advanced Cluster Management for Kubernetes
• Ubuntu update for linux
• Multiple vulnerabilities in Red Hat Advanced Cluster Management for Kubernetes 2.2