CVE-2024-21597
Junos OS: MX Series: In an AF scenario traffic can bypass configured lo0 firewall filters
An Exposure of Resource to Wrong Sphere vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on MX Series allows an unauthenticated, network-based attacker to bypass the intended access restrictions.
In an Abstracted Fabric (AF) scenario if routing-instances (RI) are configured, specific valid traffic destined to the device can bypass the configured lo0 firewall filters as it's received in the wrong RI context.
This issue affects Juniper Networks Junos OS on MX Series:
- All versions earlier than 20.4R3-S9;
- 21.2 versions earlier than 21.2R3-S3;
- 21.4 versions earlier than 21.4R3-S5;
- 22.1 versions earlier than 22.1R3;
- 22.2 versions earlier than 22.2R3;
- 22.3 versions earlier than 22.3R2.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Junos OS: MX Series: In an AF scenario traffic can bypass configured lo0 firewall filters
An Exposure of Resource to Wrong Sphere vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on MX Series allows an unauthenticated, network-based attacker to bypass the intended access restrictions.
In an Abstracted Fabric (AF) scenario if routing-instances (RI) are configured, specific valid traffic destined to the device can bypass the configured lo0 firewall filters as it's received in the wrong RI context.
This issue affects Juniper Networks Junos OS on MX Series:
- All versions earlier than 20.4R3-S9;
- 21.2 versions earlier than 21.2R3-S3;
- 21.4 versions earlier than 21.4R3-S5;
- 22.1 versions earlier than 22.1R3;
- 22.2 versions earlier than 22.2R3;
- 22.3 versions earlier than 22.3R2.
- Record
CVE-2024-21597- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-668
- Updated
- 2026-11-02
EUVDEUVD-2024-19245
An Exposure of Resource to Wrong Sphere vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on MX Series allows an unauthenticated, network-based attacker to bypass the intended access restrictions.
In an Abstracted Fabric (AF) scenario if routing-instances (RI) are configured, specific valid traffic destined to the device can bypass the configured lo0 firewall filters as it's received in the wrong RI context.
This issue affects Juniper Networks Junos OS on MX Series:
- All versions earlier than 20.4R3-S9;
- 21.2 versions earlier than 21.2R3-S3;
- 21.4 versions earlier than 21.4R3-S5;
- 22.1 versions earlier than 22.1R3;
- 22.2 versions earlier than 22.2R3;
- 22.3 versions earlier than 22.3R2.
- Record
EUVD-2024-19245- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-m474-q42g-p73p
An Exposure of Resource to Wrong Sphere vulnerability in the Packet Forwarding Engine (PFE) of...
An Exposure of Resource to Wrong Sphere vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on MX Series allows an unauthenticated, network-based attacker to bypass the intended access restrictions.
In an Abstracted Fabric (AF) scenario if routing-instances (RI) are configured, specific valid traffic destined to the device can bypass the configured lo0 firewall filters as it's received in the wrong RI context.
This issue affects Juniper Networks Junos OS on MX Series:
- All versions earlier than 20.4R3-S9;
- 21.2 versions earlier than 21.2R3-S3;
- 21.4 versions earlier than 21.4R3-S5;
- 22.1 versions earlier than 22.1R3;
- 22.2 versions earlier than 22.2R3;
- 22.3 versions earlier than 22.3R2.
- Record
GHSA-m474-q42g-p73p- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-668
- Updated
- 2026-11-02
NVD
An Exposure of Resource to Wrong Sphere vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on MX Series allows an unauthenticated, network-based attacker to bypass the intended access restrictions.
In an Abstracted Fabric (AF) scenario if routing-instances (RI) are configured, specific valid traffic destined to the device can bypass the configured lo0 firewall filters as it's received in the wrong RI context.
This issue affects Juniper Networks Junos OS on MX Series:
- All versions earlier than 20.4R3-S9;
- 21.2 versions earlier than 21.2R3-S3;
- 21.4 versions earlier than 21.4R3-S5;
- 22.1 versions earlier than 22.1R3;
- 22.2 versions earlier than 22.2R3;
- 22.3 versions earlier than 22.3R2.
- Record
CVE-2024-21597- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-668
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2024-21597 is a medium vulnerability (CVSS 5.3) in Juniper Junos, published January 12, 2024. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.38%, the 31st percentile. No source names a fixed version.