Junos OS (SRX firewalls)
CVE-2024-39550: MX Series with SPC3 line card: Port flaps causes rtlogd memory leak leading to Denial of Service
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).
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| Junos OS (MX Series with SPC3) 21.2R3 | 21.2R3-S8 or later |
| Junos OS (MX Series with SPC3) 21.4R2 | 21.4R3-S6 or later |
| Junos OS (MX Series with SPC3) 22.1 | 22.1R3-S5 or later |
| Junos OS (MX Series with SPC3) 22.2 | 22.2R3-S3 or later |
| Junos OS (MX Series with SPC3) 22.3 | 22.3R3-S2 or later |
| Junos OS (MX Series with SPC3) 22.4 | 22.4R3-S1 or later |
| Junos OS (MX Series with SPC3) 23.2 | 23.2R2 or later |
| Junos OS (MX Series with SPC3) 23.4 | 23.4R2 or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
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.
Am I affected?
Next Gen Services can be enabled by using this command:
user@host> request system enable unified-services
After you enter request system enable unified-services, reboot the chassis.
Workarounds
There are no known workarounds for this issue.
Exploitation
Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 13 Oct 2026.