Junos OS and Junos OS Evolved: In an EVPN-MPLS scenario churn of ESI routes causes a memory leak in l2ald
A Missing Release of Memory after Effective Lifetime vulnerability in the Layer 2 Address Learning Daemon (l2ald) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent, unauthenticated attacker to cause a memory leak ultimately leading to a Denial of Service (DoS).
In an EVPN-MPLS scenario, routes learned from remote multi-homed Provider Edge (PE) devices are programmed as ESI routes. Due to a logic issue in the l2ald memory management, memory allocated for these routes is not released when there is churn for these routes. As a result, memory leaks in the l2ald process which will ultimately lead to a crash and restart of l2ald.
Use the following command to monitor the memory consumption by l2ald:
user@device> show system process extensive | match "PID|l2ald"
This issue affects:
Junos OS:
* all versions before 22.4R3-S5,
* 23.2 versions before 23.2R2-S3,
* 23.4 versions before 23.4R2-S4,
* 24.2 versions before 24.2R2;
Junos OS Evolved:
* all versions before 22.4R3-S5-EVO,
* 23.2 versions before 23.2R2-S3-EVO,
* 23.4 versions before 23.4R2-S4-EVO,
* 24.2 versions before 24.2R2-EVO.
Problem Types
| Type | CWE ID | Description |
|---|
| CWE | CWE-401 | CWE-401 Missing Release of Memory after Effective Lifetime |
Type: CWE
Description: CWE-401 Missing Release of Memory after Effective Lifetime
Metrics
| Version | Base score | Base severity | Vector |
|---|
| 3.1 | 6.5 | MEDIUM | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 4.0 | 7.1 | HIGH | CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/RE:M |
Version: 3.1
Base score: 6.5
Base severity: MEDIUM
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Version: 4.0
Base score: 7.1
Base severity: HIGH
Vector: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/RE:M