CVE-2024-39561 MEDIUM

CVE-2024-39561: Junos OS: SRX4600, SRX5000 Series: TCP packets with SYN/FIN or SYN/RST are transferred after enabling no-syn-check with Express Path

Vendor Juniper Networks
Product Junos OS
Weakness CWE-754
Published July 10, 2024
Last update August 2, 2024

CVSS base score

5.8/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity Low

CVSS vector

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

What the vulnerability does

01Description

An Improper Check for Unusual or Exceptional Conditions vulnerability in the flow daemon (flowd) of Juniper Networks Junos OS on SRX4600 and SRX5000 Series allows an attacker to send TCP packets with SYN/FIN or SYN/RST flags, bypassing the expected blocking of these packets. A TCP packet with SYN/FIN or SYN/RST should be dropped in flowd. However, when no-syn-check and Express Path are enabled, these TCP packets are unexpectedly transferred to the downstream network. This issue affects Junos OS on SRX4600 and SRX5000 Series: * All versions before 21.2R3-S8, * from 21.4 before 21.4R3-S7, * from 22.1 before 22.1R3-S6, * from 22.2 before 22.2R3-S4, * from 22.3 before 22.3R3-S3, * from 22.4 before 22.4R3-S2, * from 23.2 before 23.2R2, * from 23.4 before 23.4R1-S1, 23.4R2.

Key dates

02Disclosure timeline

July 10, 2024 CVE published
August 2, 2024 Record updated