CVE-2019-0048 Security feature bypass in Junos OS
Attackers can bypass firewall filters on multicast traffic in Juniper EX4300 switches when TCAM optimization is enabled and a loopback filter is applied.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2019-0048?
CVE-2019-0048 is a medium-severity vulnerability in Juniper Junos, published on 11 Jul 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
On EX4300 Series switches with TCAM optimization enabled, incoming multicast traffic matches an implicit loopback filter rule first, since it has high priority. This rule is meant for reserved multicast addresses 224.0.0.x, but incorrectly matches on 224.x.x.x. Due to this bug, when a firewall filter is applied on the loopback interface, other firewall filters might stop working for multicast traffic. The command 'show firewall filter' can be used to confirm whether the filter is working. This issue only affects the EX4300 switch. No other products or platforms are affected by this vulnerability. This issue affects: Juniper Networks Junos OS: 14.1X53 versions prior to 14.1X53-D51, 14.1X53-D115 on EX4300 Series; 17.1 versions prior to 17.1R3 on EX4300 Series; 17.2 versions prior to 17.2R3-S2 on EX4300 Series; 17.3 versions prior to 17.3R3-S3 on EX4300 Series; 17.4 versions prior to 17.4R2-S5, 17.4R3 on EX4300 Series; 18.1 versions prior to 18.1R3-S1 on EX4300 Series; 18.2 versions prior to 18.2R2 on EX4300 Series; 18.3 versions prior to 18.3R2 on EX4300 Series.
Weakness: CWE-200
Which versions are affected by CVE-2019-0048?
It affects 1 product.
Products include Juniper Junos.
How do I fix CVE-2019-0048?
No fix has been published for CVE-2019-0048 yet. Limit exposure of the affected software until one is available.
Is CVE-2019-0048 being exploited?
There is no known exploitation of CVE-2019-0048 in the wild and no public exploit code.
Other vulnerabilities in Juniper Junos
- CVE-2023-36845 Juniper Junos OS EX Series and SRX Series PHP External Variable Modification
- CVE-2020-1631 Juniper Junos OS Path Traversal
- CVE-2025-21590 Juniper Junos OS Improper Isolation or Compartmentalization
- CVE-2023-36851 Juniper Junos OS SRX Series Missing Authentication for Critical Function
- CVE-2023-36844 Juniper Junos OS EX Series PHP External Variable Modification
Sources
Also known as GHSA-5p6g-hf22-qx2m.