CVE-2024-39557
Junos OS Evolved: MAC table changes cause a memory leak
An Uncontrolled Resource Consumption vulnerability in the
Layer 2 Address Learning Daemon (l2ald)
of Juniper Networks Junos OS Evolved allows an unauthenticated, adjacent attacker to cause a memory leak, eventually exhausting all system memory, leading to a system crash and Denial of Service (DoS).
Certain MAC table updates cause a small amount of memory to leak. Once memory utilization reaches its limit, the issue will result in a system crash and restart.
To identify the issue, execute the CLI command:
user@device> show platform application-info allocations app l2ald-agent EVL Object Allocation Statistics:
Node Application Context Name Live Allocs Fails Guids re0 l2ald-agent net::juniper::rtnh::L2Rtinfo 1069096 1069302 0 1069302 re0 l2ald-agent net::juniper::rtnh::NHOpaqueTlv 114 195 0 195
This issue affects Junos OS Evolved:
-
All versions before 21.4R3-S8-EVO,
-
from 22.2-EVO before 22.2R3-S4-EVO,
-
from 22.3-EVO before 22.3R3-S3-EVO,
-
from 22.4-EVO before 22.4R3-EVO,
-
from 23.2-EVO before 23.2R2-EVO.
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
7.1
Junos OS Evolved: MAC table changes cause a memory leak
An Uncontrolled Resource Consumption vulnerability in the
Layer 2 Address Learning Daemon (l2ald)
of Juniper Networks Junos OS Evolved allows an unauthenticated, adjacent attacker to cause a memory leak, eventually exhausting all system memory, leading to a system crash and Denial of Service (DoS).
Certain MAC table updates cause a small amount of memory to leak. Once memory utilization reaches its limit, the issue will result in a system crash and restart.
To identify the issue, execute the CLI command:
user@device> show platform application-info allocations app l2ald-agent EVL Object Allocation Statistics:
Node Application Context Name Live Allocs Fails Guids re0 l2ald-agent net::juniper::rtnh::L2Rtinfo 1069096 1069302 0 1069302 re0 l2ald-agent net::juniper::rtnh::NHOpaqueTlv 114 195 0 195
This issue affects Junos OS Evolved:
-
All versions before 21.4R3-S8-EVO,
-
from 22.2-EVO before 22.2R3-S4-EVO,
-
from 22.3-EVO before 22.3R3-S3-EVO,
-
from 22.4-EVO before 22.4R3-EVO,
-
from 23.2-EVO before 23.2R2-EVO.
- Record
CVE-2024-39557- CVSS 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/R:A - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-400
- Updated
- 2026-11-02
EUVDEUVD-2024-38083
7.1
An Uncontrolled Resource Consumption vulnerability in the
Layer 2 Address Learning Daemon (l2ald)
of Juniper Networks Junos OS Evolved allows an unauthenticated, adjacent attacker to cause a memory leak, eventually exhausting all system memory, leading to a system crash and Denial of Service (DoS).
Certain MAC table updates cause a small amount of memory to leak. Once memory utilization reaches its limit, the issue will result in a system crash and restart.
To identify the issue, execute the CLI command:
user@device> show platform application-info allocations app l2ald-agent EVL Object Allocation Statistics:
Node Application Context Name Live Allocs Fails Guids re0 l2ald-agent net::juniper::rtnh::L2Rtinfo 1069096 1069302 0 1069302 re0 l2ald-agent net::juniper::rtnh::NHOpaqueTlv 114 195 0 195
This issue affects Junos OS Evolved:
-
All versions before 21.4R3-S8-EVO,
-
from 22.2-EVO before 22.2R3-S4-EVO,
-
from 22.3-EVO before 22.3R3-S3-EVO,
-
from 22.4-EVO before 22.4R3-EVO,
-
from 23.2-EVO before 23.2R2-EVO.
- Record
EUVD-2024-38083- CVSS 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/R:A - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-g26w-g327-7xm5
7.1
An Uncontrolled Resource Consumption vulnerability in the Layer 2 Address Learning Daemon ...
An Uncontrolled Resource Consumption vulnerability in the
Layer 2 Address Learning Daemon (l2ald)
of Juniper Networks Junos OS Evolved allows an unauthenticated, adjacent attacker to cause a memory leak, eventually exhausting all system memory, leading to a system crash and Denial of Service (DoS).
Certain MAC table updates cause a small amount of memory to leak. Once memory utilization reaches its limit, the issue will result in a system crash and restart.
To identify the issue, execute the CLI command:
user@device> show platform application-info allocations app l2ald-agent EVL Object Allocation Statistics:
Node Application Context Name Live Allocs Fails Guids re0 l2ald-agent net::juniper::rtnh::L2Rtinfo 1069096 1069302 0 1069302 re0 l2ald-agent net::juniper::rtnh::NHOpaqueTlv 114 195 0 195
This issue affects Junos OS Evolved:
-
All versions before 21.4R3-S8-EVO,
-
from 22.2-EVO before 22.2R3-S4-EVO,
-
from 22.3-EVO before 22.3R3-S3-EVO,
-
from 22.4-EVO before 22.4R3-EVO,
-
from 23.2-EVO before 23.2R2-EVO.
- Record
GHSA-g26w-g327-7xm5- CVSS 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:A/V:X/RE:X/U:X - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-400
- Updated
- 2026-11-02
NVD
7.1
An Uncontrolled Resource Consumption vulnerability in the
Layer 2 Address Learning Daemon (l2ald)
of Juniper Networks Junos OS Evolved allows an unauthenticated, adjacent attacker to cause a memory leak, eventually exhausting all system memory, leading to a system crash and Denial of Service (DoS).
Certain MAC table updates cause a small amount of memory to leak. Once memory utilization reaches its limit, the issue will result in a system crash and restart.
To identify the issue, execute the CLI command:
user@device> show platform application-info allocations app l2ald-agent EVL Object Allocation Statistics:
Node Application Context Name Live Allocs Fails Guids re0 l2ald-agent net::juniper::rtnh::L2Rtinfo 1069096 1069302 0 1069302 re0 l2ald-agent net::juniper::rtnh::NHOpaqueTlv 114 195 0 195
This issue affects Junos OS Evolved:
-
All versions before 21.4R3-S8-EVO,
-
from 22.2-EVO before 22.2R3-S4-EVO,
-
from 22.3-EVO before 22.3R3-S3-EVO,
-
from 22.4-EVO before 22.4R3-EVO,
-
from 23.2-EVO before 23.2R2-EVO.
- Record
CVE-2024-39557- CVSS 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:A/V:X/RE:X/U:X - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-400
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2024-39557 is a high vulnerability (CVSS 7.1) in Juniper Junos Os Evolved, published July 10, 2024. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.25%, the 15th percentile. No source names a fixed version.