CVE-2023-22396: An Uncontrolled Resource Consumption vulnerability in TCP processing on the Routing Engine (RE) of Juniper Networks Junos OS allows an unauthenticated...

Description

An Uncontrolled Resource Consumption vulnerability in TCP processing on the Routing Engine (RE) of Juniper Networks Junos OS allows an unauthenticated network-based attacker to send crafted TCP packets destined to the device, resulting in an MBUF leak that ultimately leads to a Denial of Service (DoS). The system does not recover automatically and must be manually restarted to restore service. This issue occurs when crafted TCP packets are sent directly to a configured IPv4 or IPv6 interface on the device. Transit traffic will not trigger this issue. MBUF usage can be monitored through the use of the 'show system buffers' command. For example: user@junos> show system buffers | refresh 5 4054/566/4620 mbufs in use (current/cache/total) ... 4089/531/4620 mbufs in use (current/cache/total) ... 4151/589/4740 mbufs in use (current/cache/total) ... 4213/527/4740 mbufs in use (current/cache/total) This issue affects Juniper Networks Junos OS: 12.3 version 12.3R12-S19 and later versions; 15.1 version 15.1R7-S10 and later versions; 17.3 version 17.3R3-S12 and later versions; 18.4 version 18.4R3-S9 and later versions; 19.1 version 19.1R3-S7 and later versions; 19.2 version 19.2R3-S3 and later versions; 19.3 version 19.3R2-S7, 19.3R3-S3 and later versions prior to 19.3R3-S7; 19.4 version 19.4R2-S7, 19.4R3-S5 and later versions prior to 19.4R3-S10; 20.1 version 20.1R3-S1 and later versions; 20.2 version 20.2R3-S2 and later versions prior to 20.2R3-S6; 20.3 version 20.3R3-S1 and later versions prior to 20.3R3-S6; 20.4 version 20.4R2-S2, 20.4R3 and later versions prior to 20.4R3-S5; 21.1 version 21.1R2 and later versions prior to 21.1R3-S4; 21.2 version 21.2R1-S1, 21.2R2 and later versions prior to 21.2R3-S3; 21.3 versions prior to 21.3R3-S2; 21.4 versions prior to 21.4R3; 22.1 versions prior to 22.1R2-S1, 22.1R3; 22.2 versions prior to 22.2R1-S2, 22.2R2; 22.3 versions prior to 22.3R1-S1, 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

0.56%

42.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions	Update
Juniper	Junos	12.3	R12-S19
Juniper	Junos	15.1	R7-S10
Juniper	Junos	17.3	R3-S12
Juniper	Junos	18.4	R3-S10
Juniper	Junos	19.1	R3-S7
Juniper	Junos	19.2	R3-S3
Juniper	Junos	19.3	R2-S7
Juniper	Junos	19.4	—
Juniper	Junos	20.1	R3-S1
Juniper	Junos	20.2	R3-S2
Juniper	Junos	20.3	R3-S1
Juniper	Junos	20.4	R2-S2
Juniper	Junos	21.1	R2
Juniper	Junos	21.2	R1-S1
Juniper	Junos	21.3	—
Juniper	Junos	21.4	—
Juniper	Junos	22.1	R1
Juniper	Junos	22.2	R1
Juniper	Junos	22.3	R1

References

https://kb.juniper.net/JSA70192Vendor Advisory
https://kb.juniper.net/JSA70192Vendor Advisory

Timeline

Published: Jan 13, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-22396?

An Uncontrolled Resource Consumption vulnerability in TCP processing on the Routing Engine (RE) of Juniper Networks Junos OS allows an unauthenticated network-based attacker to send crafted TCP packets destined to the device, resulting in an MBUF leak that ultimately leads to a Denial of Service (DoS). The system does not recover automatically and must be manually restarted to restore service. This issue occurs when crafted TCP packets are sent directly to a configured IPv4 or IPv6 interface on the device. Transit traffic will not trigger this issue. MBUF usage can be monitored through the use of the 'show system buffers' command. For example: user@junos> show system buffers | refresh 5 4054/566/4620 mbufs in use (current/cache/total) ... 4089/531/4620 mbufs in use (current/cache/total) ... 4151/589/4740 mbufs in use (current/cache/total) ... 4213/527/4740 mbufs in use (current/cache/total) This issue affects Juniper Networks Junos OS: 12.3 version 12.3R12-S19 and later versions; 15.1 version 15.1R7-S10 and later versions; 17.3 version 17.3R3-S12 and later versions; 18.4 version 18.4R3-S9 and later versions; 19.1 version 19.1R3-S7 and later versions; 19.2 version 19.2R3-S3 and later versions; 19.3 version 19.3R2-S7, 19.3R3-S3 and later versions prior to 19.3R3-S7; 19.4 version 19.4R2-S7, 19.4R3-S5 and later versions prior to 19.4R3-S10; 20.1 version 20.1R3-S1 and later versions; 20.2 version 20.2R3-S2 and later versions prior to 20.2R3-S6; 20.3 version 20.3R3-S1 and later versions prior to 20.3R3-S6; 20.4 version 20.4R2-S2, 20.4R3 and later versions prior to 20.4R3-S5; 21.1 version 21.1R2 and later versions prior to 21.1R3-S4; 21.2 version 21.2R1-S1, 21.2R2 and later versions prior to 21.2R3-S3; 21.3 versions prior to 21.3R3-S2; 21.4 versions prior to 21.4R3; 22.1 versions prior to 22.1R2-S1, 22.1R3; 22.2 versions prior to 22.2R1-S2, 22.2R2; 22.3 versions prior to 22.3R1-S1, 22.3R2.

How severe is CVE-2023-22396?

CVE-2023-22396 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.56% probability of exploitation in the next 30 days.

How do I fix CVE-2023-22396?

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.