Junos OS (SRX firewalls)
CVE-2024-21598: A malformed BGP tunnel encapsulation attribute will lead to an rpd crash
An Improper Validation of Syntactic Correctness of Input vulnerability in the Routing Protocol Daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows a network-based, unauthenticated attacker to cause a Denial of Service (DoS).
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| Junos OS 20.4 | 20.4R3-S9 or later |
| Junos OS 21.2 | 21.2R3-S7 or later |
| Junos OS 21.3 | 21.3R3-S5 or later |
| Junos OS 21.4 | 21.4R3-S5 or later |
| Junos OS 22.1 | 22.1R3-S4 or later |
| Junos OS 22.2 | 22.2R3-S3 or later |
| Junos OS 22.3 | 22.3R3-S1 or later |
| Junos OS 22.4 | 22.4R3 or later |
| Junos OS 23.2 | 23.2R1-S2, 23.2R2 or later |
| Junos OS Evolved 20.4-EVO | 20.4R3-S9-EVO or later |
| Junos OS Evolved 21.2-EVO | 21.2R3-S7-EVO or later |
| Junos OS Evolved 21.3-EVO | 21.3R3-S5-EVO or later |
| Junos OS Evolved 21.4-EVO | 21.4R3-S5-EVO or later |
| Junos OS Evolved 22.1-EVO | 22.1R3-S4-EVO or later |
| Junos OS Evolved 22.2-EVO | 22.2R3-S3-EVO or later |
| Junos OS Evolved 22.3-EVO | 22.3R3-S1-EVO or later |
| Junos OS Evolved 22.4-EVO | 22.4R3-EVO or later |
| Junos OS Evolved 23.2-EVO | 23.2R1-S2-EVO, 23.2R2-EVO or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
An Improper Validation of Syntactic Correctness of Input vulnerability in the Routing Protocol Daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows a network-based, unauthenticated attacker to cause a Denial of Service (DoS).
If a BGP update is received over an established BGP session which contains a tunnel encapsulation attribute with a specifically malformed TLV, rpd will crash and restart.
This issue affects Juniper Networks Junos OS: * 20.4 versions 20.4R1 and later 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 22.4R3; * 23.2 versions earlier than 23.2R1-S2, 23.2R2;
Junos OS Evolved: * 20.4-EVO versions 20.4R1-EVO and later versions earlier than 20.4R3-S9-EVO; * 21.2-EVO versions earlier than 21.2R3-S7-EVO; * 21.3-EVO versions earlier than 21.3R3-S5-EVO; * 21.4-EVO versions earlier than 21.4R3-S5-EVO; * 22.1-EVO versions earlier than 22.1R3-S4-EVO; * 22.2-EVO versions earlier than 22.2R3-S3-EVO; * 22.3-EVO versions earlier than 22.3R3-S1-EVO; * 22.4-EVO versions earlier than 22.4R3-EVO; * 23.2-EVO versions earlier than 23.2R1-S2-EVO, 23.2R2-EVO;
This issue does not affect Juniper Networks * Junos OS versions earlier than 20.4R1; * Junos OS Evolved versions earlier than 20.4R1-EVO.
This is a related but separate issue than the one described in JSA79095.
Am I affected?
To be exposed to this vulnerability BGP needs to be configured as in the following example, but no further options need to be enabled:
[ protocols bgp group <group> neighbor ... ]
Workarounds
There are no known workarounds for this issue.
Exploitation
Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 13 Oct 2026.