CVE-2024-39540

HIGH

Published Jul 11, 2024 Modified Apr 11, 2025 CWE-754

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 MX Series with SPC3 allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). When an affected device receives specific valid TCP traffic, the pfe crashes and restarts leading to a momentary but complete service outage. This issue affects Junos OS: 21.2 releases from 21.2R3-S5 before 21.2R3-S6. This issue does not affect earlier or later releases.

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CVSS v3.1 Score

7.5

HIGH

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

Weakness Type (CWE)

CWE-754 CWE-754

Affected Products

Vendor	Product	Versions
juniper	junos	All
juniper	csrx	All
juniper	mx240	All
juniper	mx480	All
juniper	mx960	All
juniper	srx100	All
juniper	srx110	All
juniper	srx1400	All
juniper	srx1500	All
juniper	srx1600	All
juniper	srx210	All
juniper	srx220	All
juniper	srx2300	All
juniper	srx240	All
juniper	srx240h2	All
juniper	srx240m	All
juniper	srx300	All
juniper	srx320	All
juniper	srx340	All
juniper	srx3400	All
juniper	srx345	All
juniper	srx3600	All
juniper	srx380	All
juniper	srx4000	All
juniper	srx4100	All
juniper	srx4200	All
juniper	srx4300	All
juniper	srx4600	All
juniper	srx4700	All
juniper	srx5000	All
juniper	srx5400	All
juniper	srx550	All
juniper	srx550_hm	All
juniper	srx550m	All
juniper	srx5600	All
juniper	srx5800	All
juniper	srx650	All
juniper	vsrx	All

References

Advisories & Patches

https://supportportal.juniper.net/JSA83000 https://supportportal.juniper.net/JSA83000

Frequently Asked Questions

What is CVE-2024-39540? +

How severe is CVE-2024-39540? +

CVE-2024-39540 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2024-39540? +

CVE-2024-39540 affects products from juniper, specifically: csrx, junos, mx240, mx480, mx960, srx100, srx110, srx1400, srx1500, srx1600, srx210, srx220, srx2300, srx240, srx240h2, srx240m, srx300, srx320, srx340, srx3400, srx345, srx3600, srx380, srx4000, srx4100, srx4200, srx4300, srx4600, srx4700, srx5000, srx5400, srx550, srx550_hm, srx550m, srx5600, srx5800, srx650, vsrx. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2024-39540? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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