CVE-2021-0295 MEDIUM

CVE-2021-0295: Junos OS: QFX10K Series: Denial of Service (DoS) upon receipt of DVMRP packets received on multi-homing ESI in VXLAN.

Vendor Juniper Networks
Product Junos OS
Weakness CWE-697
Published July 15, 2021
Last update September 17, 2024

CVSS base score

6.1/10
Attack vector Adjacent
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity Low

CVSS vector

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L

What the vulnerability does

01Description

A vulnerability in the Distance Vector Multicast Routing Protocol (DVMRP) of Juniper Networks Junos OS on the QFX10K Series switches allows an attacker to trigger a packet forwarding loop, leading to a partial Denial of Service (DoS). The issue is caused by DVMRP packets looping on a multi-homed Ethernet Segment Identifier (ESI) when VXLAN is configured. DVMRP 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: 17.3 versions prior to 17.3R3-S12; 17.4 versions prior to 17.4R3-S5; 18.1 versions prior to 18.1R3-S13; 18.2 version 18.2R1 and later versions; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R2-S9, 18.4R3-S8; 19.1 versions prior to 19.1R3-S5; 19.2 versions prior to 19.2R1-S7, 19.2R3-S2; 19.3 versions prior to 19.3R3-S2; 19.4 versions prior to 19.4R3-S3; 20.1 versions prior to 20.1R2-S2, 20.1R3; 20.2 versions prior to 20.2R3; 20.3 versions prior to 20.3R3; 20.4 versions prior to 20.4R2.

Key dates

02Disclosure timeline

July 15, 2021 CVE published
September 17, 2024 Record updated