CVE-2024-21586

Junos OS: SRX Series and NFX Series: Specific valid traffic leads to a PFE crash

HIGH

7.5

CVSS Score

Published: July 1, 2024 at 04:34 PM UTC

Updated: June 17, 2026 at 07:09 AM UTC

1 product affected across 1 vendorJunos

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Severity

HIGH7.5

Exploit prediction

EPSS 0.5%

SSVC

No known exploit

Description

An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on SRX Series and NFX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). If an affected device receives specific valid traffic destined to the device, it will cause the PFE to crash and restart. Continued receipt and processing of this traffic will create a sustained DoS condition. This issue affects Junos OS on SRX Series: * 21.4 versions before 21.4R3-S7.9, * 22.1 versions before 22.1R3-S5.3, * 22.2 versions before 22.2R3-S4.11, * 22.3 versions before 22.3R3, * 22.4 versions before 22.4R3. This issue affects Junos OS on NFX Series: * 21.4 versions before 21.4R3-S8, * 22.1 versions after 22.1R1, * 22.2 versions before 22.2R3-S5, * 22.3 versions before 22.3R3, * 22.4 versions before 22.4R3. Junos OS versions prior to 21.4R1 are not affected by this issue.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Junos · Juniper Networks

95%

v < 21.4r121.4 ≤ v < 21.4R3-S7.921.4 ≤ v < 21.4R3-S821.4 ≤ v < 21.4r3-s7.922.1 ≤ v < 22.1R3-S5.322.1 ≤ v < 22.1r3-s5.322.2 ≤ v < 22.2R3-S4.1122.2 ≤ v < 22.2R3-S522.2 ≤ v < 22.2r3-s4.1122.3 ≤ v < 22.3R322.3 ≤ v < 22.3r322.4 ≤ v < 22.4R322.4 ≤ v < 22.4r321.4 21.4 r1 21.4 r1-s1 21.4 r1-s2 21.4 r2 21.4 r2-s1 21.4 r2-s2 21.4 r3 21.4 r3-s1 21.4 r3-s2 21.4 r3-s3 21.4 r3-s4 21.4 r3-s5 21.4 r3-s6 21.4 r3-s7 22.1 22.1 r1 22.1 r1-s1 22.1 r1-s2 22.1 r2 22.1 r2-s1 22.1 r2-s2 22.1 r3 22.1 r3-s1 22.1 r3-s2 22.1 r3-s3 22.1 r3-s4 22.1 r3-s5 22.2 22.2 r1 22.2 r1-s1 22.2 r1-s2 22.2 r2 22.2 r2-s1 22.2 r2-s2 22.2 r3 22.2 r3-s1 22.2 r3-s2 22.2 r3-s3 22.2 r3-s4 22.3 22.3 r1 22.3 r1-s1 22.3 r1-s2 22.3 r2 22.3 r2-s1 22.3 r2-s2 22.4 22.4 r1 22.4 r1-s1 22.4 r1-s2 22.4 r2 22.4 r2-s1 22.4 r2-s2

Vendor states this is fixed in 21.4R1 (unaffected)

Affected range stops below 21.4R3-S7.9, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.4R3-S8, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.1R3-S5.3, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.2R3-S4.11, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.2R3-S5, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.3R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.4R3, so it looks safe — our inference, not a vendor statement

juniper-nfx150 (environment) · juniper-nfx250 (environment) · juniper-nfx350 (environment) · juniper-srx1500 (environment) · juniper-srx1600 (environment) · juniper-srx2300 (environment) · juniper-srx300 (environment) · juniper-srx320 (environment) · juniper-srx340 (environment) · juniper-srx345 (environment) · juniper-srx380 (environment) · juniper-srx4100 (environment) · juniper-srx4120 (environment) · juniper-srx4200 (environment) · juniper-srx4300 (environment) · juniper-srx4600 (environment) · juniper-srx4700 (environment) · juniper-srx5400 (environment) · juniper-srx5600 (environment) · juniper-srx5800 (environment)