Ubuntu update for linux

Published: 2021-04-13

Risk	Medium
Patch available	YES
Number of vulnerabilities	4
CVE-ID	CVE-2021-20194 CVE-2021-26930 CVE-2021-26931 CVE-2021-3348
CWE-ID	CWE-122 CWE-399 CWE-770 CWE-416
Exploitation vector	Network
Public exploit	N/A
Vulnerable software	Ubuntu Operating systems & Components / Operating system linux-image-raspi (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-gkeop (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-virtual (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-raspi2 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-oracle (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-oem-osp1 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-oem (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-lowlatency (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-kvm (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-gkeop-5.4 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-generic-lpae (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-generic (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-gcp (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-azure (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-aws (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-5.4.0-71-lowlatency (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-5.4.0-71-generic-lpae (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-5.4.0-71-generic (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-5.4.0-1044-azure (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-5.4.0-1043-aws (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-5.4.0-1042-oracle (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-5.4.0-1041-gcp (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-5.4.0-1037-kvm (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-5.4.0-1033-raspi (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-5.4.0-1013-gkeop (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-gke-5.4 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-5.4.0-1040-gke (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-virtual-hwe-18.04 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-snapdragon-hwe-18.04 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-raspi-hwe-18.04 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-lowlatency-hwe-18.04 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-generic-lpae-hwe-18.04 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-generic-hwe-18.04 (Ubuntu package) Operating systems & Components / Operating system package or component
Vendor	Canonical Ltd.

Security Bulletin

This security bulletin contains information about 4 vulnerabilities.

1) Heap-based buffer overflow

EUVDB-ID: #VU60356

Risk: Low

CVSSv4.0: 4.4 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-20194

CWE-ID: CWE-122 - Heap-based Buffer Overflow

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a boundary error within the __cgroup_bpf_run_filter_getsockopt() function, when kernel is compiled with config params CONFIG_BPF_SYSCALL=y , CONFIG_BPF=y , CONFIG_CGROUPS=y , CONFIG_CGROUP_BPF=y , CONFIG_HARDENED_USERCOPY not set, and BPF hook to getsockopt is registered. A local user can trigger a heap-based buffer overflow and execute arbitrary code with elevated privileges.

Mitigation

Update the affected package linux to the latest version.

Vulnerable software versions

Ubuntu: 18.04 - 20.04

linux-image-raspi (Ubuntu package): before 5.4.0.1033.68

linux-image-gkeop (Ubuntu package): before 5.4.0.1013.16

linux-image-virtual (Ubuntu package): before 5.4.0.71.74

linux-image-raspi2 (Ubuntu package): before 5.4.0.1033.68

linux-image-oracle (Ubuntu package): before 5.4.0.1042.39

linux-image-oem-osp1 (Ubuntu package): before 5.4.0.71.74

linux-image-oem (Ubuntu package): before 5.4.0.71.74

linux-image-lowlatency (Ubuntu package): before 5.4.0.71.74

linux-image-kvm (Ubuntu package): before 5.4.0.1037.35

linux-image-gkeop-5.4 (Ubuntu package): before 5.4.0.1013.14~18.04.14

linux-image-generic-lpae (Ubuntu package): before 5.4.0.71.74

linux-image-generic (Ubuntu package): before 5.4.0.71.74

linux-image-gcp (Ubuntu package): before 5.4.0.1041.28

linux-image-azure (Ubuntu package): before 5.4.0.1044.24

linux-image-aws (Ubuntu package): before 5.4.0.1043.26

linux-image-5.4.0-71-lowlatency (Ubuntu package): before 5.4.0-71.79~18.04.1

linux-image-5.4.0-71-generic-lpae (Ubuntu package): before 5.4.0-71.79~18.04.1

linux-image-5.4.0-71-generic (Ubuntu package): before 5.4.0-71.79~18.04.1

linux-image-5.4.0-1044-azure (Ubuntu package): before 5.4.0-1044.46~18.04.1

linux-image-5.4.0-1043-aws (Ubuntu package): before 5.4.0-1043.45~18.04.1

linux-image-5.4.0-1042-oracle (Ubuntu package): before 5.4.0-1042.45~18.04.1

linux-image-5.4.0-1041-gcp (Ubuntu package): before 5.4.0-1041.44~18.04.1

linux-image-5.4.0-1037-kvm (Ubuntu package): before 5.4.0-1037.38

linux-image-5.4.0-1033-raspi (Ubuntu package): before 5.4.0-1033.36~18.04.1

linux-image-5.4.0-1013-gkeop (Ubuntu package): before 5.4.0-1013.14~18.04.1

linux-image-gke-5.4 (Ubuntu package): before 5.4.0.1040.42~18.04.7

linux-image-5.4.0-1040-gke (Ubuntu package): before 5.4.0-1040.42~18.04.1

linux-image-virtual-hwe-18.04 (Ubuntu package): before 5.4.0.71.79~18.04.64

linux-image-snapdragon-hwe-18.04 (Ubuntu package): before 5.4.0.71.79~18.04.64

linux-image-raspi-hwe-18.04 (Ubuntu package): before 5.4.0.1033.35

linux-image-lowlatency-hwe-18.04 (Ubuntu package): before 5.4.0.71.79~18.04.64

linux-image-generic-lpae-hwe-18.04 (Ubuntu package): before 5.4.0.71.79~18.04.64

linux-image-generic-hwe-18.04 (Ubuntu package): before 5.4.0.71.79~18.04.64

CPE2.3

External links

https://ubuntu.com/security/notices/USN-4909-1

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

2) Resource management error

EUVDB-ID: #VU51587

Risk: Medium

CVSSv4.0: 4.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-26930

CWE-ID: CWE-399 - Resource Management Errors

Exploit availability: No

Description

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to improper management of internal resources when processing service requests to the PV backend within drivers/block/xen-blkback/blkback.c driver in Xen. A local user on the guest OS can perform a denial of service (DoS) attack.