medium
6.9
CWE
754
Advisory Published
Updated

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

First published: Wed Jul 10 2024(Updated: )

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.

Credit: sirt@juniper.net

Affected SoftwareAffected VersionHow to fix
All of
Any of
Junos OS Evolved<21.2
Junos OS Evolved=21.2
Junos OS Evolved=21.2-r1
Junos OS Evolved=21.2-r1-s1
Junos OS Evolved=21.2-r1-s2
Junos OS Evolved=21.2-r2
Junos OS Evolved=21.2-r2-s1
Junos OS Evolved=21.2-r2-s2
Junos OS Evolved=21.2-r3
Junos OS Evolved=21.2-r3-s1
Junos OS Evolved=21.2-r3-s2
Junos OS Evolved=21.2-r3-s3
Junos OS Evolved=21.2-r3-s4
Junos OS Evolved=21.2-r3-s5
Junos OS Evolved=21.2-r3-s6
Junos OS Evolved=21.2-r3-s7
Junos OS Evolved=21.4
Junos OS Evolved=21.4-r1
Junos OS Evolved=21.4-r1-s1
Junos OS Evolved=21.4-r1-s2
Junos OS Evolved=21.4-r2
Junos OS Evolved=21.4-r2-s1
Junos OS Evolved=21.4-r2-s2
Junos OS Evolved=21.4-r3
Junos OS Evolved=21.4-r3-s1
Junos OS Evolved=21.4-r3-s2
Junos OS Evolved=21.4-r3-s3
Junos OS Evolved=21.4-r3-s4
Junos OS Evolved=21.4-r3-s5
Junos OS Evolved=21.4-r3-s6
Junos OS Evolved=22.1
Junos OS Evolved=22.1-r1
Junos OS Evolved=22.1-r1-s1
Junos OS Evolved=22.1-r1-s2
Junos OS Evolved=22.1-r2
Junos OS Evolved=22.1-r2-s1
Junos OS Evolved=22.1-r2-s2
Junos OS Evolved=22.1-r3
Junos OS Evolved=22.1-r3-s1
Junos OS Evolved=22.1-r3-s2
Junos OS Evolved=22.1-r3-s3
Junos OS Evolved=22.1-r3-s4
Junos OS Evolved=22.1-r3-s5
Junos OS Evolved=22.2
Junos OS Evolved=22.2-r1
Junos OS Evolved=22.2-r1-s1
Junos OS Evolved=22.2-r1-s2
Junos OS Evolved=22.2-r2
Junos OS Evolved=22.2-r2-s1
Junos OS Evolved=22.2-r2-s2
Junos OS Evolved=22.2-r3
Junos OS Evolved=22.2-r3-s1
Junos OS Evolved=22.2-r3-s2
Junos OS Evolved=22.2-r3-s3
Junos OS Evolved=22.3
Junos OS Evolved=22.3-r1
Junos OS Evolved=22.3-r1-s1
Junos OS Evolved=22.3-r1-s2
Junos OS Evolved=22.3-r2
Junos OS Evolved=22.3-r2-s1
Junos OS Evolved=22.3-r2-s2
Junos OS Evolved=22.3-r3
Junos OS Evolved=22.3-r3-s1
Junos OS Evolved=22.3-r3-s2
Junos OS Evolved=22.4
Junos OS Evolved=22.4-r1
Junos OS Evolved=22.4-r1-s1
Junos OS Evolved=22.4-r1-s2
Junos OS Evolved=22.4-r2
Junos OS Evolved=22.4-r2-s1
Junos OS Evolved=22.4-r2-s2
Junos OS Evolved=22.4-r3
Junos OS Evolved=22.4-r3-s1
Junos OS Evolved=23.2
Junos OS Evolved=23.2-r1
Junos OS Evolved=23.2-r1-s1
Junos OS Evolved=23.2-r1-s2
Junos OS Evolved=23.4
Junos OS Evolved=23.4-r1
Any of
Juniper SRX4600
Junos OS SRX 5000 Series
Juniper SRX5400
Juniper SRX5600
Juniper SRX5800
Juniper JUNOS<21.2R3-S8>=undefined<21.4R3-S7>=undefined<22.1R3-S6>=undefined<22.2R3-S4>=undefined<22.3R3-S3>=undefined<22.4R3-S2>=undefined<23.2R2>=undefined<23.4R1-S1

Remedy

The following software releases have been updated to resolve this specific issue: 21.2R3-S8, 21.4R3-S7, 22.1R3-S6, 22.2R3-S4, 22.3R3-S3, 22.4R3-S2, 23.2R2, 23.4R1-S1, 23.4R2, 24.2R1, and all subsequent releases.

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Reference Links

Frequently Asked Questions

  • What is the severity of CVE-2024-39561?

    CVE-2024-39561 is considered a high severity vulnerability due to the potential for attackers to bypass security measures.

  • How does CVE-2024-39561 affect Junos OS?

    CVE-2024-39561 affects the flow daemon in Junos OS, allowing attackers to send TCP packets with improper flags.

  • How do I fix CVE-2024-39561?

    To fix CVE-2024-39561, upgrade to the patched versions of Junos OS as specified in the security advisory.

  • What devices are impacted by CVE-2024-39561?

    CVE-2024-39561 impacts Juniper Networks SRX4600 and SRX5000 Series devices running vulnerable versions of Junos OS.

  • What are the implications of CVE-2024-39561 for network security?

    CVE-2024-39561 can lead to unauthorized access and manipulation of network traffic, significantly compromising network security.

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