CVE-2022-22217: Junos OS: QFX10K Series: Denial of Service (DoS) upon receipt of crafted MLD packets on multi-homing ESI in VXLAN

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2022-07-20 · updated 2026-06-17
Weakness: CWE-754

Description

An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS allows an adjacent unauthenticated attacker to cause a Denial of Service (DoS). The issue is caused by malformed MLD packets looping on a multi-homed Ethernet Segment Identifier (ESI) when VXLAN is configured. These MLD packets received on a multi-homed ESI are sent to the peer, and then incorrectly forwarded out the same ESI, violating the split horizon rule. This issue only affects QFX10K Series switches, including the QFX10002, QFX10008, and QFX10016. Other products and platforms are unaffected by this vulnerability. This issue affects Juniper Networks Junos OS on QFX10K Series: All versions prior to 19.1R3-S9; 19.2 versions prior to 19.2R1-S9, 19.2R3-S5; 19.3 versions prior to 19.3R3-S6; 19.4 versions prior to 19.4R2-S7, 19.4R3-S8; 20.1 versions prior to 20.1R3-S4; 20.2 versions prior to 20.2R3-S4; 20.3 versions prior to 20.3R3-S2; 20.4 versions prior to 20.4R3-S2; 21.1 versions prior to 21.1R3; 21.2 versions prior to 21.2R2-S1, 21.2R3; 21.3 versions prior to 21.3R2.

Affected products

Juniper Junos OS: before 19.1; 19.1, 19.1-r1, 19.1-r1-s1, 19.1-r1-s2, 19.1-r1-s3, 19.1-r1-s4 (+125) — fixed in 19.1

How to fix

Upgrade to a fixed version: Juniper Junos OS 19.1. Check the vendor advisory for mitigations.

References

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