CVE-2024-39561

Summary

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.

Affected Software

VendorProductVersion RangeStatus
Juniper NetworksJunos OS0 < 21.2R3-S8affected
Juniper NetworksJunos OS21.4 < 21.4R3-S7affected
Juniper NetworksJunos OS22.1 < 22.1R3-S6affected
Juniper NetworksJunos OS22.2 < 22.2R3-S4affected
Juniper NetworksJunos OS22.3 < 22.3R3-S3affected
Juniper NetworksJunos OS22.4 < 22.4R3-S2affected
Juniper NetworksJunos OS23.2 < 23.2R2affected
Juniper NetworksJunos OS23.4 < 23.4R1-S1, 23.4R2affected

Weaknesses

  • CWE-754: CWE-754 Improper Check for Unusual or Exceptional Conditions

Workarounds

This issue can be mitigated by disabling Express Path:

[set security forwarding-options services-offload disable]

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: partial

CVE Program Container

Additional References

References