Multiple vulnerabilities in Linux Kernel

Published: 2018-12-05 | Updated: 2018-12-17

Risk	Low
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2018-19824 CVE-2018-18397
CWE-ID	CWE-416 CWE-264
Exploitation vector	Local
Public exploit	Public exploit code for vulnerability #1 is available. Public exploit code for vulnerability #2 is available.
Vulnerable software Subscribe	Linux kernel Operating systems & Components / Operating system
Vendor	Linux Foundation

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Use-after-free error

EUVDB-ID: #VU16237

Risk: Low

CVSSv3.1: 7.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2018-19824

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

The vulnerability allows a local attacker to gain elevated privileges on the target system.

The vulnerability exists in the Advanced Linux Sound Architecture (ALSA) driver due to use-after-free error in the usb_audio_probefunction, as defined in the sound/usb/card.c source code file. A local attacker can supply a malicious USB sound device with no interfaces, trigger memory corruption and execute arbitrary code with elevated privileges.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Linux kernel: before 4.19.6

External links

http://github.com/torvalds/linux/commit/5f8cf712582617d523120df67d392059eaf2fc4b

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) Security restrictions bypass

EUVDB-ID: #VU16558

Risk: Low

CVSSv3.1: 4.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C]

CVE-ID: CVE-2018-18397

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: Yes

Description

The vulnerability allows a local attacker to bypass security restrictions on the target system.

The vulnerability exists due to improper access control in the userfaultfd implementation. A local attacker can access a system that is mounted with shmem or hugetlbs virtual memory areas, maliciously modify mapping to targeted files and write arbitrary memory on the system, which could be used to conduct additional attacks.