Ubuntu update for linux

Published: 2021-07-20

Risk	Low
Patch available	YES
Number of vulnerabilities	12
CVE-ID	CVE-2021-33909 CVE-2021-33200 CVE-2020-24586 CVE-2020-24587 CVE-2020-26139 CVE-2020-26147 CVE-2020-26558 CVE-2021-0129 CVE-2021-23134 CVE-2021-31829 CVE-2021-32399 CVE-2021-33034
CWE-ID	CWE-190 CWE-787 CWE-20 CWE-254 CWE-284 CWE-416 CWE-200 CWE-362
Exploitation vector	Local network
Public exploit	Public exploit code for vulnerability #1 is available.
Vulnerable software	Ubuntu Operating systems & Components / Operating system linux-image-oem (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-gke (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-virtual-hwe-16.04 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-lowlatency-hwe-16.04 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-generic-hwe-16.04 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-aws-hwe (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-snapdragon (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-lts-18.04 (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-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-lts-18.04 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-azure-lts-18.04 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-aws-lts-18.04 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.15.0-151-lowlatency (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.15.0-151-generic-lpae (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.15.0-151-generic (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.15.0-1121-azure (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.15.0-1109-snapdragon (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.15.0-1109-aws (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.15.0-1106-gcp (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.15.0-1097-kvm (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.15.0-1092-raspi2 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.15.0-1078-oracle (Ubuntu package) Operating systems & Components / Operating system package or component
Vendor	Canonical Ltd.

Security Bulletin

This security bulletin contains information about 12 vulnerabilities.

1) Integer overflow

EUVDB-ID: #VU55143

Risk: Low

CVSSv4.0: 7.1 [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:P/U:Clear]

CVE-ID: CVE-2021-33909

CWE-ID: CWE-190 - Integer overflow

Exploit availability: Yes

Description

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

The vulnerability exists due to integer overflow during size_t-to-int conversion when creating, mounting, and deleting a deep directory structure whose total path length exceeds 1GB. An unprivileged local user can write up to 10-byte string to an offset of exactly -2GB-10B below the beginning of a vmalloc()ated kernel buffer.

Successful exploitation of vulnerability may allow an attacker to exploit the our-of-bounds write vulnerability to execute arbitrary code with root privileges.

Mitigation

Update the affected package linux to the latest version.

Vulnerable software versions

Ubuntu: 14.04 - 18.04

linux-image-oem (Ubuntu package): before 5.4.0.202.198

linux-image-oracle (Ubuntu package): before 6.8.0-1017.18~22.04.1

linux-image-gke (Ubuntu package): before 6.8.0-1015.19

linux-image-gcp (Ubuntu package): before 6.8.0-1019.21~22.04.1

linux-image-azure (Ubuntu package): before 6.8.0-1018.21~22.04.1

linux-image-virtual-hwe-16.04 (Ubuntu package): before 4.15.0.210.193

linux-image-lowlatency-hwe-16.04 (Ubuntu package): before 4.15.0.210.193

linux-image-generic-hwe-16.04 (Ubuntu package): before 4.15.0.210.193

linux-image-aws-hwe (Ubuntu package): before Ubuntu Pro (Infra-only)

linux-image-virtual (Ubuntu package): before 4.15.0.151.139

linux-image-snapdragon (Ubuntu package): before 4.15.0.1109.112

linux-image-raspi2 (Ubuntu package): before 4.15.0.1092.90

linux-image-oracle-lts-18.04 (Ubuntu package): before 4.15.0.1078.88

linux-image-lowlatency (Ubuntu package): before 4.15.0.151.139

linux-image-kvm (Ubuntu package): before 4.15.0.1097.93

linux-image-generic-lpae (Ubuntu package): before 4.15.0.151.139

linux-image-generic (Ubuntu package): before 4.15.0.151.139

linux-image-gcp-lts-18.04 (Ubuntu package): before 4.15.0.1106.125

linux-image-azure-lts-18.04 (Ubuntu package): before 4.15.0.1121.94

linux-image-aws-lts-18.04 (Ubuntu package): before 4.15.0.1109.112

linux-image-4.15.0-151-lowlatency (Ubuntu package): before 4.15.0-151.157

linux-image-4.15.0-151-generic-lpae (Ubuntu package): before 4.15.0-151.157

linux-image-4.15.0-151-generic (Ubuntu package): before 4.15.0-151.157

linux-image-4.15.0-1121-azure (Ubuntu package): before 4.15.0-1121.134

linux-image-4.15.0-1109-snapdragon (Ubuntu package): before 4.15.0-1109.118

linux-image-4.15.0-1109-aws (Ubuntu package): before 4.15.0-1109.116

linux-image-4.15.0-1106-gcp (Ubuntu package): before 4.15.0-1106.120

linux-image-4.15.0-1097-kvm (Ubuntu package): before 4.15.0-1097.99

linux-image-4.15.0-1092-raspi2 (Ubuntu package): before 4.15.0-1092.98

linux-image-4.15.0-1078-oracle (Ubuntu package): before 4.15.0-1078.86

CPE2.3

External links

https://ubuntu.com/security/notices/USN-5018-1

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. However, proof of concept for this vulnerability is available.

2) Out-of-bounds write

EUVDB-ID: #VU87989

Risk: Low

CVSSv4.0: 5.9 [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:U/U:Clear]

CVE-ID: CVE-2021-33200

CWE-ID: CWE-787 - Out-of-bounds write

Exploit availability: No

Description

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

The vulnerability exists due to a boundary error in kernel/bpf/verifier.c. A local user can trigger an out-of-bounds write and escalate privileges on the system.