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Product Affected

This issue affects all versions of Junos OS and Junos OS Evolved.

Severity

Medium

Severity Assessment (CVSS) Score

CVSS 3.1: 6.5 (CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVSS 4.0: 7.1 (CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Problem

An Improper Check or Handling of Exceptional Conditions vulnerability in the Routing Protocol Daemon (rpd) of Juniper Networks Junos and Junos OS Evolved allows an unauthenticated, adjacent attacker to cause a Denial of Service (DoS).

An attacker can send specific traffic to the device, which causes the rpd to crash and restart. Continued receipt of this traffic will result in a sustained DoS condition.

This issue only affects devices with an EVPN-VPWS instance with IGMP-snooping enabled.

This issue affects Junos OS:

All versions before 20.4R3-S10,
from 21.4 before 21.4R3-S6,
from 22.1 before 22.1R3-S5,
from 22.2 before 22.2R3-S3,
from 22.3 before 22.3R3-S2,
from 22.4 before 22.4R3,
from 23.2 before 23.2R2;

Junos OS Evolved:

All versions before 20.4R3-S10-EVO,
from 21.4-EVO before 21.4R3-S6-EVO,
from 22.1-EVO before 22.1R3-S5-EVO,
from 22.2-EVO before 22.2R3-S3-EVO,
from 22.3-EVO before 22.3R3-S2-EVO,
from 22.4-EVO before 22.4R3-EVO,
from 23.2-EVO before 23.2R2-EVO.

Required configuration for exposure:

EVPN-VPWS can be configured with the following:
[ routing-instances <instance-name> instance-type evpn-vpws ] [ routing-instances <instance-name> interface <interface> ]

IGMP-snooping can be enabled with the following configuration line:
[ routing-instances <instance-name> bridge-domains <name> igmp-snooping vlan <vlan> ]

Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

This issue was seen during production usage.

Solution

The following software releases have been updated to resolve this specific issue:
Junos OS: 20.4R3-S10, 21.4R3-S6, 22.1R3-S5, 22.2R3-S3, 22.3R3-S2, 22.4R3, 23.2R2, 23.4R1, and all subsequent releases.
Junos OS Evolved: 20.4R3-S10-EVO, 21.4R3-S6-EVO, 22.1R3-S5-EVO, 22.2R3-S3-EVO, 22.3R3-S2-EVO, 22.4R3-EVO, 23.2R2-EVO, 23.4R1-EVO, and all subsequent releases.

This issue is being tracked as 1758171 which is visible on the Customer Support website.

Note: Juniper SIRT's policy is not to evaluate releases which are beyond End of Engineering (EOE) or End of Life (EOL).

Workaround

Deactivating IGMP snooping for the EVPN-VPWS instance stops the issue from occurring.

Severity Assessment

Information for how Juniper Networks uses CVSS can be found at KB 16446 [juniper.net] "Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories."

Modification History