Improper Privilege Management in Linux kernel - CVE-2021-41073

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Main Vulnerability Database Vulnerabilities #VU68300

Improper Privilege Management in Linux kernel - CVE-2021-41073

Published: October 13, 2022 / Updated: October 19, 2022


Vulnerability identifier: #VU68300
CSH Severity: Low
CVSS v4: 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]
CVE-ID: CVE-2021-41073
CWE-ID: CWE-269
Exploitation vector: Local access
Exploit availability: Public exploit is available

Vulnerability details

The vulnerability allows a local user to escalate privileges.

The vulnerability exists due to improper privilege management within the loop_rw_iter() function in fs/io_uring.c in Linux kernel. A local user can escalate privileges on the system by using IORING_OP_PROVIDE_BUFFERS to trigger a free of a kernel buffer.


Affected software

Linux kernel
Ubuntu
Fedora
linux-image-5.10.0-1049-oem (Ubuntu package)
linux-image-oem-20.04 (Ubuntu package)
linux-image-oem-20.04b (Ubuntu package)
linux-image-generic (Ubuntu package)
linux-image-virtual (Ubuntu package)
linux-image-lowlatency (Ubuntu package)
linux-image-generic-64k (Ubuntu package)
linux-image-generic-lpae (Ubuntu package)
linux-image-5.11.0-37-generic-64k (Ubuntu package)
linux-image-5.11.0-37-generic (Ubuntu package)
linux-image-5.11.0-37-generic-lpae (Ubuntu package)
linux-image-5.11.0-37-lowlatency (Ubuntu package)
linux-image-generic-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-64k-hwe-20.04 (Ubuntu package)
linux-image-virtual-hwe-20.04 (Ubuntu package)
linux-image-5.11.0-1017-kvm (Ubuntu package)
linux-image-kvm (Ubuntu package)
linux-image-azure (Ubuntu package)
linux-image-5.11.0-1017-azure (Ubuntu package)
linux-image-azure-edge (Ubuntu package)
linux-image-raspi (Ubuntu package)
linux-image-raspi-nolpae (Ubuntu package)
linux-image-5.11.0-1019-raspi (Ubuntu package)
linux-image-5.11.0-1019-raspi-nolpae (Ubuntu package)
linux-image-5.11.0-1019-oracle (Ubuntu package)
linux-image-5.11.0-1019-azure (Ubuntu package)
linux-image-5.11.0-1019-aws (Ubuntu package)
linux-image-oracle (Ubuntu package)
linux-image-aws (Ubuntu package)
linux-image-gke (Ubuntu package)
linux-image-gcp (Ubuntu package)
linux-image-5.11.0-1020-gcp (Ubuntu package)
linux-image-5.13.0-1014-oem (Ubuntu package)
linux-image-oem-20.04c (Ubuntu package)
kernel
kernel-headers
kernel-tools

How to mitigate CVE-2021-41073

Install updates from vendor's website.

linux-image-5.10.0-1049-oem (Ubuntu package) - update to 5.10.0-1049.51
linux-image-oem-20.04 (Ubuntu package) - addressed in versions 5.10.0.1049.51, 5.11.0.37.39
linux-image-oem-20.04b (Ubuntu package) - update to 5.10.0.1049.51
linux-image-generic (Ubuntu package) - update to 5.11.0.37.39
linux-image-virtual (Ubuntu package) - update to 5.11.0.37.39
linux-image-lowlatency (Ubuntu package) - update to 5.11.0.37.39
linux-image-generic-64k (Ubuntu package) - update to 5.11.0.37.39
linux-image-generic-lpae (Ubuntu package) - update to 5.11.0.37.39
linux-image-5.11.0-37-generic-64k (Ubuntu package) - update to 5.11.0-37.41~20.04.2
linux-image-5.11.0-37-generic (Ubuntu package) - update to 5.11.0-37.41~20.04.2
linux-image-5.11.0-37-generic-lpae (Ubuntu package) - update to 5.11.0-37.41~20.04.2
linux-image-5.11.0-37-lowlatency (Ubuntu package) - update to 5.11.0-37.41~20.04.2
linux-image-generic-hwe-20.04 (Ubuntu package) - update to 5.11.0.37.41~20.04.16
linux-image-lowlatency-hwe-20.04 (Ubuntu package) - update to 5.11.0.37.41~20.04.16
linux-image-generic-lpae-hwe-20.04 (Ubuntu package) - update to 5.11.0.37.41~20.04.16
linux-image-generic-64k-hwe-20.04 (Ubuntu package) - update to 5.11.0.37.41~20.04.16
linux-image-virtual-hwe-20.04 (Ubuntu package) - update to 5.11.0.37.41~20.04.16
linux-image-5.11.0-1017-kvm (Ubuntu package) - update to 5.11.0-1017.18
linux-image-kvm (Ubuntu package) - update to 5.11.0.1017.18
linux-image-azure (Ubuntu package) - addressed in versions 5.11.0.1017.18, 5.11.0.1019.20
linux-image-5.11.0-1017-azure (Ubuntu package) - update to 5.11.0-1017.18~20.04.1
linux-image-azure-edge (Ubuntu package) - addressed in versions 5.11.0.1017.18~20.04.16, 5.11.0.1019.20~20.04.18
linux-image-raspi (Ubuntu package) - update to 5.11.0.1019.17
linux-image-raspi-nolpae (Ubuntu package) - update to 5.11.0.1019.17
linux-image-5.11.0-1019-raspi (Ubuntu package) - update to 5.11.0-1019.20
linux-image-5.11.0-1019-raspi-nolpae (Ubuntu package) - update to 5.11.0-1019.20
linux-image-5.11.0-1019-oracle (Ubuntu package) - update to 5.11.0-1019.20~20.04.1
linux-image-5.11.0-1019-azure (Ubuntu package) - update to 5.11.0-1019.20~20.04.1
linux-image-5.11.0-1019-aws (Ubuntu package) - update to 5.11.0-1019.20~20.04.1
linux-image-oracle (Ubuntu package) - update to 5.11.0.1019.20~20.04.12
linux-image-aws (Ubuntu package) - update to 5.11.0.1019.20~20.04.18
linux-image-gke (Ubuntu package) - update to 5.11.0.1020.20
linux-image-gcp (Ubuntu package) - update to 5.11.0.1020.20
linux-image-5.11.0-1020-gcp (Ubuntu package) - update to 5.11.0-1020.22
linux-image-5.13.0-1014-oem (Ubuntu package) - update to 5.13.0-1014.18
linux-image-oem-20.04c (Ubuntu package) - update to 5.13.0.1014.18
kernel - addressed in versions 5.14.7-100.fc33, 5.14.7-200.fc34, 5.14.9-100.fc33, 5.14.9-200.fc34
kernel-headers - addressed in versions 5.14.7-100.fc33, 5.14.7-200.fc34, 5.14.9-100.fc33, 5.14.9-200.fc34
kernel-tools - addressed in versions 5.14.7-100.fc33, 5.14.7-200.fc34, 5.14.9-100.fc33, 5.14.9-200.fc34

Links to Public Exploits and PoC-codes

External References

Related Security Bulletins