Vulnerability identifier: #VU19144

Vulnerability risk: Medium

CVSSv3.1: 5.1 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-0048

CWE-ID: CWE-399

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Juniper Junos OS
Operating systems & Components / Operating system

Vendor: Juniper Networks, Inc.

Description

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

The vulnerability exists due to incoming multicast traffic matches an implicit loopback filter rule first, since it has high priority. Due to this bug, when a firewall filter is applied on the loopback interface, other firewall filters might stop working for multicast traffic. A remote attacker can send a specially crafted request to the loopback interface to stop other firewall filters work.

This issue only affects the EX4300 switch with TCAM optimization enabled:

• set system packet-forwarding-options tcam-group-optimization

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Juniper Junos OS: 14.1x53 - 14.1X53-D50, 17.1 - 17.1R2-S10, 17.2 - 17.2R3-S1, 17.3 - 17.3R3-S2, 17.4 - 17.4R2-S4, 18.1 - 18.1R3, 18.2 - 18.2R2-S1, 18.3 - 18.3R1-S4

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External links
http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10942&cat=SIRT_1&actp=LIST

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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.