Ubuntu update for linux

Published: 2021-01-28

Risk	High
Patch available	YES
Number of vulnerabilities	5
CVE-ID	CVE-2018-13093 CVE-2019-19813 CVE-2019-19816 CVE-2020-25669 CVE-2020-27777
CWE-ID	CWE-476 CWE-416 CWE-787 CWE-862
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-4.4.0-201-powerpc64-smp (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-201-powerpc64-emb (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-201-powerpc-smp (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-201-powerpc-e500mc (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-201-lowlatency (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-201-generic-lpae (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-4.4.0-201-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-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-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
Vendor	Canonical Ltd.

Security Bulletin

This security bulletin contains information about 5 vulnerabilities.

1) Null pointer dereference

EUVDB-ID: #VU13853

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-2018-13093

CWE-ID: CWE-476 - NULL Pointer Dereference

Exploit availability: No

Description

The vulnerability allows a local attacker to cause DoS condition on the target system.

The vulnerability exists in the lookup_slow() function in the Extended File System (XFS) component, as defined in the source code file fs/xfs/xfs_icache.c due to boundary error when mounting XFS filesystems. A local attacker can mount an XFS filesystem that submits malicious input, trigger NULL pointer dereference memory error and cause the affected software to terminate abnormally.

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 4.4.0.201.176

linux-image-powerpc64-smp-lts-xenial (Ubuntu package): before 4.4.0.201.176

linux-image-powerpc64-emb-lts-xenial (Ubuntu package): before 4.4.0.201.176

linux-image-powerpc-smp-lts-xenial (Ubuntu package): before 4.4.0.201.176

linux-image-powerpc-e500mc-lts-xenial (Ubuntu package): before 4.4.0.201.176

linux-image-lowlatency-lts-xenial (Ubuntu package): before 4.4.0.201.176

linux-image-generic-lts-xenial (Ubuntu package): before 4.4.0.201.176

linux-image-generic-lpae-lts-xenial (Ubuntu package): before 4.4.0.201.176

linux-image-4.4.0-201-powerpc64-smp (Ubuntu package): before 4.4.0-201.233~14.04.1

linux-image-4.4.0-201-powerpc64-emb (Ubuntu package): before 4.4.0-201.233~14.04.1

linux-image-4.4.0-201-powerpc-smp (Ubuntu package): before 4.4.0-201.233~14.04.1

linux-image-4.4.0-201-powerpc-e500mc (Ubuntu package): before 4.4.0-201.233~14.04.1

linux-image-4.4.0-201-lowlatency (Ubuntu package): before 4.4.0-201.233~14.04.1

linux-image-4.4.0-201-generic-lpae (Ubuntu package): before 4.4.0-201.233~14.04.1

linux-image-4.4.0-201-generic (Ubuntu package): before 4.4.0-201.233~14.04.1

linux-image-virtual (Ubuntu package): before 4.4.0.201.207

linux-image-powerpc64-smp (Ubuntu package): before 4.4.0.201.207

linux-image-powerpc64-emb (Ubuntu package): before 4.4.0.201.207

linux-image-powerpc-smp (Ubuntu package): before 4.4.0.201.207

linux-image-powerpc-e500mc (Ubuntu package): before 4.4.0.201.207

linux-image-lowlatency (Ubuntu package): before 4.4.0.201.207

linux-image-generic-lpae (Ubuntu package): before 4.4.0.201.207

linux-image-generic (Ubuntu package): before 4.4.0.201.207

CPE2.3

External links

https://ubuntu.com/security/notices/USN-4708-1

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) Use-after-free

EUVDB-ID: #VU34962

Risk: Medium

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

CVE-ID: CVE-2019-19813

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

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

In the Linux kernel 5.0.21, mounting a crafted btrfs filesystem image, performing some operations, and then making a syncfs system call can lead to a use-after-free in __mutex_lock in kernel/locking/mutex.c. This is related to mutex_can_spin_on_owner in kernel/locking/mutex.c, __btrfs_qgroup_free_meta in fs/btrfs/qgroup.c, and btrfs_insert_delayed_items in fs/btrfs/delayed-inode.c.