CVE-2024-21617
Junos OS: BGP flap on NSR-enabled devices causes memory leak
An Incomplete Cleanup vulnerability in Nonstop active routing (NSR) component of Juniper Networks Junos OS allows an adjacent, unauthenticated attacker to cause memory leak leading to Denial of Service (DoS).
On all Junos OS platforms, when NSR is enabled, a BGP flap will cause memory leak. A manual reboot of the system will restore the services.
Note: NSR is not supported on the SRX Series and is therefore not affected by this vulnerability. The memory usage can be monitored using the below commands.
user@host> show chassis routing-engine no-forwarding user@host> show system memory | no-more This issue affects:
Juniper Networks Junos OS
- 21.2 versions earlier than 21.2R3-S5;
- 21.3 versions earlier than 21.3R3-S4;
- 21.4 versions earlier than 21.4R3-S4;
- 22.1 versions earlier than 22.1R3-S2;
- 22.2 versions earlier than 22.2R3-S2;
- 22.3 versions earlier than 22.3R2-S1, 22.3R3;
- 22.4 versions earlier than 22.4R1-S2, 22.4R2.
This issue does not affect Junos OS versions earlier than 20.4R3-S7.
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
Junos OS: BGP flap on NSR-enabled devices causes memory leak
An Incomplete Cleanup vulnerability in Nonstop active routing (NSR) component of Juniper Networks Junos OS allows an adjacent, unauthenticated attacker to cause memory leak leading to Denial of Service (DoS).
On all Junos OS platforms, when NSR is enabled, a BGP flap will cause memory leak. A manual reboot of the system will restore the services.
Note: NSR is not supported on the SRX Series and is therefore not affected by this vulnerability. The memory usage can be monitored using the below commands.
user@host> show chassis routing-engine no-forwarding user@host> show system memory | no-more This issue affects:
Juniper Networks Junos OS
- 21.2 versions earlier than 21.2R3-S5;
- 21.3 versions earlier than 21.3R3-S4;
- 21.4 versions earlier than 21.4R3-S4;
- 22.1 versions earlier than 22.1R3-S2;
- 22.2 versions earlier than 22.2R3-S2;
- 22.3 versions earlier than 22.3R2-S1, 22.3R3;
- 22.4 versions earlier than 22.4R1-S2, 22.4R2.
This issue does not affect Junos OS versions earlier than 20.4R3-S7.
- Record
CVE-2024-21617- 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-459
- Updated
- 2026-11-02
EUVDEUVD-2024-19265
An Incomplete Cleanup vulnerability in Nonstop active routing (NSR) component of Juniper Networks Junos OS allows an adjacent, unauthenticated attacker to cause memory leak leading to Denial of Service (DoS).
On all Junos OS platforms, when NSR is enabled, a BGP flap will cause memory leak. A manual reboot of the system will restore the services.
Note: NSR is not supported on the SRX Series and is therefore not affected by this vulnerability. The memory usage can be monitored using the below commands.
user@host> show chassis routing-engine no-forwarding user@host> show system memory | no-more This issue affects:
Juniper Networks Junos OS
- 21.2 versions earlier than 21.2R3-S5;
- 21.3 versions earlier than 21.3R3-S4;
- 21.4 versions earlier than 21.4R3-S4;
- 22.1 versions earlier than 22.1R3-S2;
- 22.2 versions earlier than 22.2R3-S2;
- 22.3 versions earlier than 22.3R2-S1, 22.3R3;
- 22.4 versions earlier than 22.4R1-S2, 22.4R2.
This issue does not affect Junos OS versions earlier than 20.4R3-S7.
- Record
EUVD-2024-19265- 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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-mmpf-h3x8-v558
An Incomplete Cleanup vulnerability in Nonstop active routing (NSR) component of Juniper...
An Incomplete Cleanup vulnerability in Nonstop active routing (NSR) component of Juniper Networks Junos OS allows an adjacent, unauthenticated attacker to cause memory leak leading to Denial of Service (DoS).
On all Junos OS platforms, when NSR is enabled, a BGP flap will cause memory leak. A manual reboot of the system will restore the services.
The memory usage can be monitored using the below commands.
user@host> show chassis routing-engine no-forwarding user@host> show system memory | no-more This issue affects:
Juniper Networks Junos OS
- 21.2 versions earlier than 21.2R3-S5;
- 21.3 versions earlier than 21.3R3-S4;
- 21.4 versions earlier than 21.4R3-S4;
- 22.1 versions earlier than 22.1R3-S2;
- 22.2 versions earlier than 22.2R3-S2;
- 22.3 versions earlier than 22.3R2-S1, 22.3R3;
- 22.4 versions earlier than 22.4R1-S2, 22.4R2.
This issue does not affect Junos OS versions earlier than 20.4R3-S7.
- Record
GHSA-mmpf-h3x8-v558- 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-459
- Updated
- 2026-11-02
NVD
An Incomplete Cleanup vulnerability in Nonstop active routing (NSR) component of Juniper Networks Junos OS allows an adjacent, unauthenticated attacker to cause memory leak leading to Denial of Service (DoS).
On all Junos OS platforms, when NSR is enabled, a BGP flap will cause memory leak. A manual reboot of the system will restore the services.
Note: NSR is not supported on the SRX Series and is therefore not affected by this vulnerability. The memory usage can be monitored using the below commands.
user@host> show chassis routing-engine no-forwarding user@host> show system memory | no-more This issue affects:
Juniper Networks Junos OS
- 21.2 versions earlier than 21.2R3-S5;
- 21.3 versions earlier than 21.3R3-S4;
- 21.4 versions earlier than 21.4R3-S4;
- 22.1 versions earlier than 22.1R3-S2;
- 22.2 versions earlier than 22.2R3-S2;
- 22.3 versions earlier than 22.3R2-S1, 22.3R3;
- 22.4 versions earlier than 22.4R1-S2, 22.4R2.
This issue does not affect Junos OS versions earlier than 20.4R3-S7.
- Record
CVE-2024-21617- 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-459
- 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-2024-21617 is a medium vulnerability (CVSS 6.5) 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 0.28%, the 21st percentile. No source names a fixed version.