Vulnerability identifier: #VU30584

Vulnerability risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-19227

CWE-ID: CWE-476

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

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 AppleTalk subsystem in the Linux kernel before 5.1, there is a potential NULL pointer dereference because register_snap_client may return NULL. This will lead to denial of service in net/appletalk/aarp.c and net/appletalk/ddp.c, as demonstrated by unregister_snap_client, aka CID-9804501fa122. A remote attacker can perform a denial of service (DoS) attack.

Mitigation
Update to version 5.1.

Vulnerable software versions

Linux kernel: 5.0 - 5.0.21

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External links
http://lists.opensuse.org/opensuse-security-announce/2019-12/msg00029.html
http://packetstormsecurity.com/files/155890/Slackware-Security-Advisory-Slackware-14.2-kernel-Updates.html
http://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.1
http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9804501fa1228048857910a6bf23e085aade37cc
http://lists.debian.org/debian-lts-announce/2020/01/msg00013.html
http://lists.debian.org/debian-lts-announce/2020/03/msg00001.html
http://seclists.org/bugtraq/2020/Jan/10
http://security.netapp.com/advisory/ntap-20200103-0001/
http://usn.ubuntu.com/4254-1/
http://usn.ubuntu.com/4254-2/
http://usn.ubuntu.com/4258-1/
http://usn.ubuntu.com/4287-1/
http://usn.ubuntu.com/4287-2/

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.