CVE-2021-0295 — MEDIUM (6.1)

Vulnerability Description

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.

CVSS Score

6.1

MEDIUM

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

Attack Vector

ADJACENT_NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

CHANGED

Confidentiality

NONE

Integrity

LOW

Availability

LOW

Affected Products

Vendor	Product	Versions
Juniper	Junos	17.3
Juniper	Qfx10000	-
Juniper	Qfx10002	-
Juniper	Qfx10008	-
Juniper	Qfx10016	-

Related Weaknesses (CWE)

CWE-697

References

https://kb.juniper.net/JSA11208Vendor Advisory
https://kb.juniper.net/JSA11208Vendor Advisory

FAQ

What is CVE-2021-0295?

CVE-2021-0295 is a vulnerability with a CVSS score of 6.1 (MEDIUM). 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 ...

How severe is CVE-2021-0295?

CVE-2021-0295 has been rated MEDIUM with a CVSS base score of 6.1/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2021-0295?

Check the references section above for vendor advisories and patch information. Affected products include: Juniper Junos, Juniper Qfx10000, Juniper Qfx10002, Juniper Qfx10008, Juniper Qfx10016.