Remote denial of service in OpenBSD npppd

1) Input validation error

EUVDB-ID: #VU80933

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: N/A

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

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

The vulnerability exists due to insufficient validation of user-supplied input within the npppd(8) daemon. A remote attacker can send a specially crafted L2TP message with a wrong AVP length to the server and perform a denial of service (DoS) attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

OpenBSD: 7.2 - 7.3

External links

http://www.openbsd.org/errata73.html#016
http://www.openbsd.org/errata72.html#038
http://ftp.openbsd.org/pub/OpenBSD/patches/7.3/common/016_npppd.patch.sig
http://ftp.openbsd.org/pub/OpenBSD/patches/7.2/common/038_npppd.patch.sig

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.