PT-2021-5047 · Juniper Networks · Junos

Published 2021-10-13 · Updated 2021-10-25 · CVE-2021-31376

Positive Technologies (AI Summary)

CVSS v2.0

7.8

High

Base vector

AV:N/AC:L/Au:N/C:N/I:N/A:C

Name of the Vulnerable Software and Affected Versions Juniper Networks Junos OS on ACX500, ACX1000, ACX1100, ACX2100, ACX2200, ACX4000, ACX5048, ACX5096 versions 18.4R3-S7 through 18.4R3-S8

Description An Improper Input Validation vulnerability in the Packet Forwarding Engine manager (FXPC) process allows an attacker to cause a Denial of Service (DoS) by sending specific DHCPv6 packets to the device and crashing the FXPC service. Continued receipt and processing of this specific packet will create a sustained Denial of Service (DoS) condition.

Recommendations For Juniper Networks Junos OS on ACX500, ACX1000, ACX1100, ACX2100, ACX2200, ACX4000, ACX5048, ACX5096 version 18.4R3-S7 and later versions prior to 18.4R3-S8, update to version 18.4R3-S8 or later to resolve the issue. As a temporary workaround, consider restricting access to the vulnerable FXPC service until a patch is available. Avoid sending specific DHCPv6 packets to the device to minimize the risk of exploitation.

Fix

DoS

RCE

Weakness Enumeration

CWE-20

Related Identifiers

BDU:2021-05817

CVE-2021-31376

Affected Products

Junos

References · 7

• https://bdu.fstec.ru/vul/2021-05817 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2021-31376 · Security Note
• https://osv.dev/vulnerability/CVE-2021-31376 · Vendor Advisory
• https://kb.juniper.net/JSA11241 · Vendor Advisory
• https://kb.juniper.net/InfoCenter/index?page=content&id=JSA11241&actp=METADATA · Note
• https://kb.juniper.net/InfoCenter/index?page=content&id=JSA11241&actp=METADATA · Note
• https://t.me/cibsecurity/30830 · Telegram Post