CVE-2024-21585
Junos OS and Junos OS Evolved: BGP session flaps on NSR-enabled devices can cause rpd crash
An Improper Handling of Exceptional Conditions vulnerability in BGP session processing of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated network-based attacker, using specific timing outside the attacker's control, to flap BGP sessions and cause the routing protocol daemon (rpd) process to crash and restart, leading to a Denial of Service (DoS) condition. Continued BGP session flapping will create a sustained Denial of Service (DoS) condition.
This issue only affects routers configured with non-stop routing (NSR) enabled. Graceful Restart (GR) helper mode, enabled by default, is also required for this issue to be exploitable.
Note: NSR is not supported on the SRX Series and is therefore not affected by this vulnerability. When the BGP session flaps on the NSR-enabled router, the device enters GR-helper/LLGR-helper mode due to the peer having negotiated GR/LLGR-restarter capability and the backup BGP requests for replication of the GR/LLGR-helper session, master BGP schedules, and initiates replication of GR/LLGR stale routes to the backup BGP. In this state, if the BGP session with the BGP peer comes up again, unsolicited replication is initiated for the peer without cleaning up the ongoing GR/LLGR-helper mode replication. This parallel two instances of replication for the same peer leads to the assert if the BGP session flaps again.
This issue affects:
Juniper Networks Junos OS
- All versions earlier than 20.4R3-S9;
- 21.2 versions earlier than 21.2R3-S7;
- 21.3 versions earlier than 21.3R3-S5;
- 21.4 versions earlier than 21.4R3-S5;
- 22.1 versions earlier than 22.1R3-S4;
- 22.2 versions earlier than 22.2R3-S3;
- 22.3 versions earlier than 22.3R3-S1;
- 22.4 versions earlier than 22.4R2-S2, 22.4R3;
- 23.2 versions earlier than 23.2R1-S1, 23.2R2.
Juniper Networks Junos OS Evolved
- All versions earlier than 21.3R3-S5-EVO;
- 21.4 versions earlier than 21.4R3-S5-EVO;
- 22.1 versions earlier than 22.1R3-S4-EVO;
- 22.2 versions earlier than 22.2R3-S3-EVO;
- 22.3 versions earlier than 22.3R3-S1-EVO;
- 22.4 versions earlier than 22.4R2-S2-EVO, 22.4R3-EVO;
- 23.2 versions earlier than 23.2R1-S1-EVO, 23.2R2-EVO.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- 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 and Junos OS Evolved: BGP session flaps on NSR-enabled devices can cause rpd crash
An Improper Handling of Exceptional Conditions vulnerability in BGP session processing of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated network-based attacker, using specific timing outside the attacker's control, to flap BGP sessions and cause the routing protocol daemon (rpd) process to crash and restart, leading to a Denial of Service (DoS) condition. Continued BGP session flapping will create a sustained Denial of Service (DoS) condition.
This issue only affects routers configured with non-stop routing (NSR) enabled. Graceful Restart (GR) helper mode, enabled by default, is also required for this issue to be exploitable.
Note: NSR is not supported on the SRX Series and is therefore not affected by this vulnerability. When the BGP session flaps on the NSR-enabled router, the device enters GR-helper/LLGR-helper mode due to the peer having negotiated GR/LLGR-restarter capability and the backup BGP requests for replication of the GR/LLGR-helper session, master BGP schedules, and initiates replication of GR/LLGR stale routes to the backup BGP. In this state, if the BGP session with the BGP peer comes up again, unsolicited replication is initiated for the peer without cleaning up the ongoing GR/LLGR-helper mode replication. This parallel two instances of replication for the same peer leads to the assert if the BGP session flaps again.
This issue affects:
Juniper Networks Junos OS
- All versions earlier than 20.4R3-S9;
- 21.2 versions earlier than 21.2R3-S7;
- 21.3 versions earlier than 21.3R3-S5;
- 21.4 versions earlier than 21.4R3-S5;
- 22.1 versions earlier than 22.1R3-S4;
- 22.2 versions earlier than 22.2R3-S3;
- 22.3 versions earlier than 22.3R3-S1;
- 22.4 versions earlier than 22.4R2-S2, 22.4R3;
- 23.2 versions earlier than 23.2R1-S1, 23.2R2.
Juniper Networks Junos OS Evolved
- All versions earlier than 21.3R3-S5-EVO;
- 21.4 versions earlier than 21.4R3-S5-EVO;
- 22.1 versions earlier than 22.1R3-S4-EVO;
- 22.2 versions earlier than 22.2R3-S3-EVO;
- 22.3 versions earlier than 22.3R3-S1-EVO;
- 22.4 versions earlier than 22.4R2-S2-EVO, 22.4R3-EVO;
- 23.2 versions earlier than 23.2R1-S1-EVO, 23.2R2-EVO.
- Record
CVE-2024-21585- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-755
- Updated
- 2026-11-02
EUVDEUVD-2024-19233
An Improper Handling of Exceptional Conditions vulnerability in BGP session processing of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated network-based attacker, using specific timing outside the attacker's control, to flap BGP sessions and cause the routing protocol daemon (rpd) process to crash and restart, leading to a Denial of Service (DoS) condition. Continued BGP session flapping will create a sustained Denial of Service (DoS) condition.
This issue only affects routers configured with non-stop routing (NSR) enabled. Graceful Restart (GR) helper mode, enabled by default, is also required for this issue to be exploitable.
Note: NSR is not supported on the SRX Series and is therefore not affected by this vulnerability. When the BGP session flaps on the NSR-enabled router, the device enters GR-helper/LLGR-helper mode due to the peer having negotiated GR/LLGR-restarter capability and the backup BGP requests for replication of the GR/LLGR-helper session, master BGP schedules, and initiates replication of GR/LLGR stale routes to the backup BGP. In this state, if the BGP session with the BGP peer comes up again, unsolicited replication is initiated for the peer without cleaning up the ongoing GR/LLGR-helper mode replication. This parallel two instances of replication for the same peer leads to the assert if the BGP session flaps again.
This issue affects:
Juniper Networks Junos OS
- All versions earlier than 20.4R3-S9;
- 21.2 versions earlier than 21.2R3-S7;
- 21.3 versions earlier than 21.3R3-S5;
- 21.4 versions earlier than 21.4R3-S5;
- 22.1 versions earlier than 22.1R3-S4;
- 22.2 versions earlier than 22.2R3-S3;
- 22.3 versions earlier than 22.3R3-S1;
- 22.4 versions earlier than 22.4R2-S2, 22.4R3;
- 23.2 versions earlier than 23.2R1-S1, 23.2R2.
Juniper Networks Junos OS Evolved
- All versions earlier than 21.3R3-S5-EVO;
- 21.4 versions earlier than 21.4R3-S5-EVO;
- 22.1 versions earlier than 22.1R3-S4-EVO;
- 22.2 versions earlier than 22.2R3-S3-EVO;
- 22.3 versions earlier than 22.3R3-S1-EVO;
- 22.4 versions earlier than 22.4R2-S2-EVO, 22.4R3-EVO;
- 23.2 versions earlier than 23.2R1-S1-EVO, 23.2R2-EVO.
- Record
EUVD-2024-19233- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-3r4r-ffrp-777w
An Improper Handling of Exceptional Conditions vulnerability in BGP session processing of...
An Improper Handling of Exceptional Conditions vulnerability in BGP session processing of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated network-based attacker, using specific timing outside the attacker's control, to flap BGP sessions and cause the routing protocol daemon (rpd) process to crash and restart, leading to a Denial of Service (DoS) condition. Continued BGP session flapping will create a sustained Denial of Service (DoS) condition.
This issue only affects routers configured with non-stop routing (NSR) enabled. Graceful Restart (GR) helper mode, enabled by default, is also required for this issue to be exploitable.
When the BGP session flaps on the NSR-enabled router, the device enters GR-helper/LLGR-helper mode due to the peer having negotiated GR/LLGR-restarter capability and the backup BGP requests for replication of the GR/LLGR-helper session, master BGP schedules, and initiates replication of GR/LLGR stale routes to the backup BGP. In this state, if the BGP session with the BGP peer comes up again, unsolicited replication is initiated for the peer without cleaning up the ongoing GR/LLGR-helper mode replication. This parallel two instances of replication for the same peer leads to the assert if the BGP session flaps again.
This issue affects:
Juniper Networks Junos OS
- All versions earlier than 20.4R3-S9;
- 21.2 versions earlier than 21.2R3-S7;
- 21.3 versions earlier than 21.3R3-S5;
- 21.4 versions earlier than 21.4R3-S5;
- 22.1 versions earlier than 22.1R3-S4;
- 22.2 versions earlier than 22.2R3-S3;
- 22.3 versions earlier than 22.3R3-S1;
- 22.4 versions earlier than 22.4R2-S2, 22.4R3;
- 23.2 versions earlier than 23.2R1-S1, 23.2R2.
Juniper Networks Junos OS Evolved
- All versions earlier than 21.3R3-S5-EVO;
- 21.4 versions earlier than 21.4R3-S5-EVO;
- 22.1 versions earlier than 22.1R3-S4-EVO;
- 22.2 versions earlier than 22.2R3-S3-EVO;
- 22.3 versions earlier than 22.3R3-S1-EVO;
- 22.4 versions earlier than 22.4R2-S2-EVO, 22.4R3-EVO;
- 23.2 versions earlier than 23.2R1-S1-EVO, 23.2R2-EVO.
- Record
GHSA-3r4r-ffrp-777w- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-755
- Updated
- 2026-11-02
NVD
An Improper Handling of Exceptional Conditions vulnerability in BGP session processing of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated network-based attacker, using specific timing outside the attacker's control, to flap BGP sessions and cause the routing protocol daemon (rpd) process to crash and restart, leading to a Denial of Service (DoS) condition. Continued BGP session flapping will create a sustained Denial of Service (DoS) condition.
This issue only affects routers configured with non-stop routing (NSR) enabled. Graceful Restart (GR) helper mode, enabled by default, is also required for this issue to be exploitable.
Note: NSR is not supported on the SRX Series and is therefore not affected by this vulnerability. When the BGP session flaps on the NSR-enabled router, the device enters GR-helper/LLGR-helper mode due to the peer having negotiated GR/LLGR-restarter capability and the backup BGP requests for replication of the GR/LLGR-helper session, master BGP schedules, and initiates replication of GR/LLGR stale routes to the backup BGP. In this state, if the BGP session with the BGP peer comes up again, unsolicited replication is initiated for the peer without cleaning up the ongoing GR/LLGR-helper mode replication. This parallel two instances of replication for the same peer leads to the assert if the BGP session flaps again.
This issue affects:
Juniper Networks Junos OS
- All versions earlier than 20.4R3-S9;
- 21.2 versions earlier than 21.2R3-S7;
- 21.3 versions earlier than 21.3R3-S5;
- 21.4 versions earlier than 21.4R3-S5;
- 22.1 versions earlier than 22.1R3-S4;
- 22.2 versions earlier than 22.2R3-S3;
- 22.3 versions earlier than 22.3R3-S1;
- 22.4 versions earlier than 22.4R2-S2, 22.4R3;
- 23.2 versions earlier than 23.2R1-S1, 23.2R2.
Juniper Networks Junos OS Evolved
- All versions earlier than 21.3R3-S5-EVO;
- 21.4 versions earlier than 21.4R3-S5-EVO;
- 22.1 versions earlier than 22.1R3-S4-EVO;
- 22.2 versions earlier than 22.2R3-S3-EVO;
- 22.3 versions earlier than 22.3R3-S1-EVO;
- 22.4 versions earlier than 22.4R2-S2-EVO, 22.4R3-EVO;
- 23.2 versions earlier than 23.2R1-S1-EVO, 23.2R2-EVO.
- Record
CVE-2024-21585- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-755
- 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-2024-21585 is a medium vulnerability (CVSS 5.9) 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 0.62%, the 50th percentile. No source names a fixed version.