high
7.5
CWE
754
Advisory Published
Updated

CVE-2023-36835: Junos OS: QFX10000 Series: All traffic will be dropped after a specific valid IP packet has been received which needs to be routed over a VXLAN tunnel

First published: Fri Jul 14 2023(Updated: )

An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on QFX10000 Series allows a network based attacker to cause a Denial of Service (DoS). If a specific valid IP packet is received and that packet needs to be routed over a VXLAN tunnel, this will result in a PFE wedge condition due to which traffic gets impacted. As this is not a crash and restart scenario, this condition will persist until the system is rebooted to recover. This issue affects Juniper Networks Junos OS on QFX10000: 20.3 version 20.3R1 and later versions; 20.4 versions prior to 20.4R3-S5; 21.1 versions prior to 21.1R3-S5; 21.2 versions prior to 21.2R3-S5; 21.3 versions prior to 21.3R3-S4; 21.4 versions prior to 21.4R3-S1; 22.1 versions prior to 22.1R3; 22.2 versions prior to 22.2R2; 22.3 versions prior to 22.3R1-S2, 22.3R2.

Credit: sirt@juniper.net sirt@juniper.net

Affected SoftwareAffected VersionHow to fix
Juniper JUNOS=20.3-r1
Juniper JUNOS=20.3-r1-s1
Juniper JUNOS=20.3-r1-s2
Juniper JUNOS=20.3-r2
Juniper JUNOS=20.3-r2-s1
Juniper JUNOS=20.3-r3
Juniper JUNOS=20.3-r3-s1
Juniper JUNOS=20.3-r3-s2
Juniper JUNOS=20.3-r3-s3
Juniper JUNOS=20.3-r3-s4
Juniper JUNOS=20.3-r3-s5
Juniper JUNOS=20.3-r3-s6
Juniper JUNOS=20.4
Juniper JUNOS=20.4-r1
Juniper JUNOS=20.4-r1-s1
Juniper JUNOS=20.4-r2
Juniper JUNOS=20.4-r2-s1
Juniper JUNOS=20.4-r2-s2
Juniper JUNOS=20.4-r3
Juniper JUNOS=20.4-r3-s1
Juniper JUNOS=20.4-r3-s2
Juniper JUNOS=20.4-r3-s3
Juniper JUNOS=20.4-r3-s4
Juniper JUNOS=21.1
Juniper JUNOS=21.1-r1
Juniper JUNOS=21.1-r1-s1
Juniper JUNOS=21.1-r2
Juniper JUNOS=21.1-r2-s1
Juniper JUNOS=21.1-r2-s2
Juniper JUNOS=21.1-r3
Juniper JUNOS=21.1-r3-s1
Juniper JUNOS=21.1-r3-s2
Juniper JUNOS=21.1-r3-s3
Juniper JUNOS=21.1-r3-s4
Juniper JUNOS=21.2
Juniper JUNOS=21.2-r1
Juniper JUNOS=21.2-r1-s1
Juniper JUNOS=21.2-r1-s2
Juniper JUNOS=21.2-r2
Juniper JUNOS=21.2-r2-s1
Juniper JUNOS=21.2-r2-s2
Juniper JUNOS=21.2-r3
Juniper JUNOS=21.2-r3-s1
Juniper JUNOS=21.2-r3-s2
Juniper JUNOS=21.2-r3-s3
Juniper JUNOS=21.2-r3-s4
Juniper JUNOS=21.3
Juniper JUNOS=21.3-r1
Juniper JUNOS=21.3-r1-s1
Juniper JUNOS=21.3-r1-s2
Juniper JUNOS=21.3-r2
Juniper JUNOS=21.3-r2-s1
Juniper JUNOS=21.3-r2-s2
Juniper JUNOS=21.3-r3
Juniper JUNOS=21.3-r3-s1
Juniper JUNOS=21.3-r3-s2
Juniper JUNOS=21.3-r3-s3
Juniper JUNOS=21.4
Juniper JUNOS=21.4-r1
Juniper JUNOS=21.4-r1-s1
Juniper JUNOS=21.4-r1-s2
Juniper JUNOS=21.4-r2
Juniper JUNOS=21.4-r2-s1
Juniper JUNOS=21.4-r2-s2
Juniper JUNOS=21.4-r3
Juniper JUNOS=22.1-r1
Juniper JUNOS=22.1-r1-s1
Juniper JUNOS=22.1-r1-s2
Juniper JUNOS=22.1-r2
Juniper JUNOS=22.1-r2-s1
Juniper JUNOS=22.1-r2-s2
Juniper JUNOS=22.2-r1
Juniper JUNOS=22.2-r1-s1
Juniper JUNOS=22.2-r1-s2
Juniper JUNOS=22.3-r1
Juniper JUNOS=22.3-r1-s1
Juniper Qfx10002
Juniper Qfx10002-60c
Juniper Qfx10008
Juniper Qfx10016

Remedy

The following software releases have been updated to resolve this specific issue: Junos OS 20.4R3-S5, 21.1R3-S5, 21.2R3-S5, 21.3R3-S4, 21.4R3-S1, 22.1R3, 22.2R2, 22.3R1-S2, 22.3R2, 22.4R1, and all subsequent releases.

Never miss a vulnerability like this again

Sign up to SecAlerts for real-time vulnerability data matched to your software, aggregated from hundreds of sources.

Read MoreStart Free Trial

Reference Links

Frequently Asked Questions

  • What is the severity of CVE-2023-36835?

    CVE-2023-36835 has been classified as having a high severity level due to its potential to enable a Denial of Service attack.

  • How do I fix CVE-2023-36835?

    To mitigate CVE-2023-36835, it is recommended to upgrade to the patched versions of Junos OS specified in the official advisory.

  • Who is affected by CVE-2023-36835?

    CVE-2023-36835 affects Juniper Networks Junos OS on various QFX10000 Series switches.

  • What kind of attack does CVE-2023-36835 allow?

    CVE-2023-36835 allows a network-based attacker to exploit the vulnerability to cause a Denial of Service (DoS) condition.

  • Is there a workaround for CVE-2023-36835?

    There are currently no known workarounds for CVE-2023-36835, making an upgrade to a secure version the only effective solution.

Company

Resources

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2025 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203