CVE-2024-39550: Junos OS: MX Series with SPC3 line card: Port flaps causes rtlogd memory leak leading to Denial of Service

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: 2024-07-11 · updated 2026-06-17
Weakness: CWE-401

Description

A Missing Release of Memory after Effective Lifetime vulnerability in the rtlogd process of Juniper Networks Junos OS on MX Series with SPC3 allows an unauthenticated, adjacent attacker to trigger internal events cause ( which can be done by repeated port flaps) to cause a slow memory leak, ultimately leading to a Denial of Service (DoS). Memory can only be recovered by manually restarting rtlogd process. The memory usage can be monitored using the below command. user@host> show system processes extensive | match rtlog This issue affects Junos OS on MX Series with SPC3 line card: * from 21.2R3 before 21.2R3-S8, * from 21.4R2 before 21.4R3-S6, * from 22.1 before 22.1R3-S5, * from 22.2 before 22.2R3-S3, * from 22.3 before 22.3R3-S2, * from 22.4 before 22.4R3-S1, * from 23.2 before 23.2R2, * from 23.4 before 23.4R2.

Affected products

Juniper Junos OS: 21.2-r3, 21.2-r3-s1, 21.2-r3-s2, 21.2-r3-s3, 21.2-r3-s4, 21.2-r3-s5 (+58)

References

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