CVE-2023-36835

HIGHCVSS 7.5/10EPSS 0.54%

Last modified

CVE-2023-36835 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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. . EPSS estimates a 0.54% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1
7.5/10

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

EPSS Probability
0.54%

41.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersionsUpdate
JuniperJunos20.3R1
JuniperJunos20.4
JuniperJunos21.1
JuniperJunos21.2
JuniperJunos21.3
JuniperJunos21.4
JuniperJunos22.1R1
JuniperJunos22.2R1
JuniperJunos22.3R1

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2023-36835?
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.
How severe is CVE-2023-36835?
CVE-2023-36835 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.54% probability of exploitation in the next 30 days.
How do I fix CVE-2023-36835?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-36835?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST