Ubuntu update for linux

Published: 2020-07-06 | Updated: 2025-04-23

Risk	Medium
Patch available	YES
Number of vulnerabilities	5
CVE-ID	CVE-2020-10690 CVE-2020-10711 CVE-2020-12770 CVE-2020-13143 CVE-2020-8992
CWE-ID	CWE-416 CWE-476 CWE-20 CWE-125 CWE-400
Exploitation vector	Network
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-4.4.0-1074-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-4.4.0-185-powerpc64-smp (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-185-powerpc64-emb (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-185-powerpc-smp (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-185-powerpc-e500mc (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-185-lowlatency (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-185-generic-lpae (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-185-generic (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-generic-lpae (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-1139-snapdragon (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-1135-raspi2 (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-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 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-1110-aws (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-1076-kvm (Ubuntu package) Operating systems & Components / Operating system package or component
Vendor	Canonical Ltd.

Security Bulletin

This security bulletin contains information about 5 vulnerabilities.

1) Use-after-free

EUVDB-ID: #VU30292

Risk: Low

CVSSv4.0: 4 [CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2020-10690

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

The vulnerability allows a local privileged user to execute arbitrary code.

There is a use-after-free in kernel versions before 5.5 due to a race condition between the release of ptp_clock and cdev while resource deallocation. When a (high privileged) process allocates a ptp device file (like /dev/ptpX) and voluntarily goes to sleep. During this time if the underlying device is removed, it can cause an exploitable condition as the process wakes up to terminate and clean all attached files. The system crashes due to the cdev structure being invalid (as already freed) which is pointed to by the inode.

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 4.4.0.185.162

linux-image-powerpc64-smp-lts-xenial (Ubuntu package): before 4.4.0.185.162

linux-image-powerpc64-emb-lts-xenial (Ubuntu package): before 4.4.0.185.162

linux-image-powerpc-smp-lts-xenial (Ubuntu package): before 4.4.0.185.162

linux-image-powerpc-e500mc-lts-xenial (Ubuntu package): before 4.4.0.185.162

linux-image-lowlatency-lts-xenial (Ubuntu package): before 4.4.0.185.162

linux-image-generic-lts-xenial (Ubuntu package): before 4.4.0.185.162

linux-image-generic-lpae-lts-xenial (Ubuntu package): before 4.4.0.185.162

linux-image-4.4.0-1074-aws (Ubuntu package): before 4.4.0-1074.78

linux-image-aws (Ubuntu package): before 4.4.0.1074.71

linux-image-4.4.0-185-powerpc64-smp (Ubuntu package): before 4.4.0-185.215~14.04.1

linux-image-4.4.0-185-powerpc64-emb (Ubuntu package): before 4.4.0-185.215~14.04.1

linux-image-4.4.0-185-powerpc-smp (Ubuntu package): before 4.4.0-185.215~14.04.1

linux-image-4.4.0-185-powerpc-e500mc (Ubuntu package): before 4.4.0-185.215~14.04.1

linux-image-4.4.0-185-lowlatency (Ubuntu package): before 4.4.0-185.215~14.04.1

linux-image-4.4.0-185-generic-lpae (Ubuntu package): before 4.4.0-185.215~14.04.1

linux-image-4.4.0-185-generic (Ubuntu package): before 4.4.0-185.215~14.04.1

linux-image-snapdragon (Ubuntu package): before 4.4.0.1139.131

linux-image-raspi2 (Ubuntu package): before 4.4.0.1135.135

linux-image-powerpc64-smp (Ubuntu package): before 4.4.0.185.191

linux-image-powerpc64-emb (Ubuntu package): before 4.4.0.185.191

linux-image-powerpc-smp (Ubuntu package): before 4.4.0.185.191

linux-image-powerpc-e500mc (Ubuntu package): before 4.4.0.185.191

linux-image-generic-lpae (Ubuntu package): before 4.4.0.185.191

linux-image-4.4.0-1139-snapdragon (Ubuntu package): before 4.4.0-1139.147

linux-image-4.4.0-1135-raspi2 (Ubuntu package): before 4.4.0-1135.144

linux-image-virtual (Ubuntu package): before 4.4.0.185.191

linux-image-lowlatency (Ubuntu package): before 4.4.0.185.191

linux-image-kvm (Ubuntu package): before 4.4.0.1076.74

linux-image-generic (Ubuntu package): before 4.4.0.185.191

linux-image-4.4.0-1110-aws (Ubuntu package): before 4.4.0-1110.121

linux-image-4.4.0-1076-kvm (Ubuntu package): before 4.4.0-1076.83

CPE2.3

External links

https://ubuntu.com/security/notices/USN-4419-1

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) NULL pointer dereference

EUVDB-ID: #VU28180

Risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-10711

CWE-ID: CWE-476 - NULL Pointer Dereference

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error in the Linux kernel's SELinux subsystem when importing the Commercial IP Security Option (CIPSO) protocol's category bitmap into the SELinux extensible bitmap via the' ebitmap_netlbl_import' routine. While processing the CIPSO restricted bitmap tag in the 'cipso_v4_parsetag_rbm' routine, it sets the security attribute to indicate that the category bitmap is present, even if it has not been allocated.

A remote attacker can send specially crafted packets the affected system, trigger a NULL pointer dereference error and crash the Linux kernel.