CVE-2021-31363 Information

Description

In an MPLS P2MP environment a Loop with Unreachable Exit Condition vulnerability in the routing protocol daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated adjacent attacker to cause high load on RPD which in turn may lead to routing protocol flaps. If a system with sensor-based-stats enabled receives a specific LDP FEC this can lead to the above condition. Continued receipted of such an LDP FEC will create a sustained Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS 19.2 version 19.2R2 and later versions prior to 19.2R3-S3; 19.3 versions prior to 19.3R2-S6 19.3R3-S2; 19.4 versions prior to 19.4R1-S4 19.4R2-S4 19.4R3-S2; 20.1 versions prior to 20.1R2-S1 20.1R3; 20.2 versions prior to 20.2R2-S1 20.2R3; 20.3 versions prior to 20.3R1-S2 20.3R2. This issue does not affect Juniper Networks Junos OS versions prior to 19.2R2. Juniper Networks Junos OS Evolved All versions prior to 20.1R2-S3-EVO; 20.3 versions prior to 20.3R1-S2-EVO.

CVSS Vector

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

Reference

https://kb.juniper.net/JSA11225

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

NONE

Base Score

HIGH

Base Severity

6.5