Ubuntu update for linux

Published: 2020-08-18 | Updated: 2025-04-23

Risk	Low
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2020-12771 CVE-2020-15393
CWE-ID	CWE-20 CWE-401
Exploitation vector	Local
Public exploit	N/A
Vulnerable software	Ubuntu Operating systems & Components / Operating system linux-image-virtual-lts-xenial (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-powerpc64-smp-lts-xenial (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-powerpc64-emb-lts-xenial (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-powerpc-smp-lts-xenial (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-powerpc-e500mc-lts-xenial (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-lowlatency-lts-xenial (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-generic-lts-xenial (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-generic-lpae-lts-xenial (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-1076-aws (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-4.4.0-187-powerpc64-smp (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-187-powerpc64-emb (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-187-powerpc-smp (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-187-powerpc-e500mc (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-187-lowlatency (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-187-generic-lpae (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-187-generic (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-powerpc64-smp (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-powerpc64-emb (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-powerpc-smp (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-powerpc-e500mc (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-4.4.0-1141-snapdragon (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-1137-raspi2 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-1112-aws (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-1078-kvm (Ubuntu package) Operating systems & Components / Operating system package or component
Vendor	Canonical Ltd.

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Input validation error

EUVDB-ID: #VU28169

Risk: Low

CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2020-12771

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

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

The vulnerability exists due to a deadlock if a coalescing operation fails in "btree_gc_coalesce" in "drivers/md/bcache/btree.c" file. A local user can pass specially crafted input to the application and perform a denial of service (DoS) attack.

Mitigation

Update the affected package linux to the latest version.

Vulnerable software versions

Ubuntu: 14.04 - 16.04

linux-image-virtual-lts-xenial (Ubuntu package): before 4.4.0.187.164

linux-image-powerpc64-smp-lts-xenial (Ubuntu package): before 4.4.0.187.164

linux-image-powerpc64-emb-lts-xenial (Ubuntu package): before 4.4.0.187.164

linux-image-powerpc-smp-lts-xenial (Ubuntu package): before 4.4.0.187.164

linux-image-powerpc-e500mc-lts-xenial (Ubuntu package): before 4.4.0.187.164

linux-image-lowlatency-lts-xenial (Ubuntu package): before 4.4.0.187.164

linux-image-generic-lts-xenial (Ubuntu package): before 4.4.0.187.164

linux-image-generic-lpae-lts-xenial (Ubuntu package): before 4.4.0.187.164

linux-image-4.4.0-1076-aws (Ubuntu package): before 4.4.0-1076.80

linux-image-aws (Ubuntu package): before 4.4.0.1076.73

linux-image-4.4.0-187-powerpc64-smp (Ubuntu package): before 4.4.0-187.217~14.04.1

linux-image-4.4.0-187-powerpc64-emb (Ubuntu package): before 4.4.0-187.217~14.04.1

linux-image-4.4.0-187-powerpc-smp (Ubuntu package): before 4.4.0-187.217~14.04.1

linux-image-4.4.0-187-powerpc-e500mc (Ubuntu package): before 4.4.0-187.217~14.04.1

linux-image-4.4.0-187-lowlatency (Ubuntu package): before 4.4.0-187.217~14.04.1

linux-image-4.4.0-187-generic-lpae (Ubuntu package): before 4.4.0-187.217~14.04.1

linux-image-4.4.0-187-generic (Ubuntu package): before 4.4.0-187.217~14.04.1

linux-image-virtual (Ubuntu package): before 4.4.0.187.193

linux-image-snapdragon (Ubuntu package): before 4.4.0.1141.133

linux-image-raspi2 (Ubuntu package): before 4.4.0.1137.137

linux-image-powerpc64-smp (Ubuntu package): before 4.4.0.187.193

linux-image-powerpc64-emb (Ubuntu package): before 4.4.0.187.193

linux-image-powerpc-smp (Ubuntu package): before 4.4.0.187.193

linux-image-powerpc-e500mc (Ubuntu package): before 4.4.0.187.193

linux-image-lowlatency (Ubuntu package): before 4.4.0.187.193

linux-image-kvm (Ubuntu package): before 4.4.0.1078.76

linux-image-generic-lpae (Ubuntu package): before 4.4.0.187.193

linux-image-generic (Ubuntu package): before 4.4.0.187.193

linux-image-4.4.0-1141-snapdragon (Ubuntu package): before 4.4.0-1141.149

linux-image-4.4.0-1137-raspi2 (Ubuntu package): before 4.4.0-1137.146

linux-image-4.4.0-1112-aws (Ubuntu package): before 4.4.0-1112.124

linux-image-4.4.0-1078-kvm (Ubuntu package): before 4.4.0-1078.85

CPE2.3

External links

https://ubuntu.com/security/notices/USN-4463-1

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) Memory leak

EUVDB-ID: #VU31921

Risk: Low

CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2020-15393

CWE-ID: CWE-401 - Missing release of memory after effective lifetime

Exploit availability: No

Description

The vulnerability allows a local user to perform DoS attack on the target system.

The vulnerability exists due memory leak in "drivers/usb/misc/usbtest.c" file. A local user can force the application to leak memory and perform denial of service attack.