CVE-2023-22395: Junos OS: In an MPLS scenario the processing of specific packets to the device causes a buffer leak and ultimately a loss of connectivity

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-01-13 · updated 2026-06-17
Weakness: CWE-401

Description

A Missing Release of Memory after Effective Lifetime vulnerability in the kernel of Juniper Networks Junos OS allows an unauthenticated, adjacent attacker to cause a Denial of Service (DoS). In an MPLS scenario specific packets destined to an Integrated Routing and Bridging (irb) interface of the device will cause a buffer (mbuf) to leak. Continued receipt of these specific packets will eventually cause a loss of connectivity to and from the device, and requires a reboot to recover. These mbufs can be monitored by using the CLI command 'show system buffers': user@host> show system buffers 783/1497/2280 mbufs in use (current/cache/total) user@host> show system buffers 793/1487/2280 mbufs in use (current/cache/total) <<<<<< mbuf usage increased This issue affects Juniper Networks Junos OS: All versions prior to 19.3R3-S7; 19.4 versions prior to 19.4R3-S9; 20.1 version 20.1R1 and later versions; 20.2 versions prior to 20.2R3-S5; 20.3 versions prior to 20.3R3-S5; 20.4 versions prior to 20.4R3-S4; 21.1 versions prior to 21.1R3-S3; 21.2 versions prior to 21.2R3-S2; 21.3 versions prior to 21.3R3-S1; 21.4 versions prior to 21.4R3; 22.1 versions prior to 22.1R2.

Affected products

Juniper Junos OS: before 19.3; 19.3, 19.3-r1, 19.3-r1-s1, 19.3-r2, 19.3-r2-s1, 19.3-r2-s2 (+117) — fixed in 19.3

How to fix

Upgrade to a fixed version: Juniper Junos OS 19.3. Check the vendor advisory for mitigations.

References

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