Junos OS (SRX firewalls)
CVE-2024-39552: Malformed BGP UPDATE causes RPD crash
An Improper Handling of Exceptional Conditions vulnerability in the routing protocol daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved allows a network based, unauthenticated attacker to cause the RPD process to crash leading to 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 0 | 20.4R3-S9 or later |
| Junos OS 21.2 | 21.2R3-S7 or later |
| Junos OS 21.3 | 21.3R3-S6 or later |
| Junos OS 21.4 | 21.4R3-S6 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-S2 or later |
| Junos OS 22.4 | 22.4R3 or later |
| Junos OS 23.2 | 23.2R2 or later |
| Junos OS Evolved 0 | 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-S8-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-S2-EVO or later |
| Junos OS Evolved 22.4-EVO | 22.4R3-EVO or later |
| Junos OS Evolved 23.2-EVO | 23.2R2-EVO or later |
| Junos OS Evolved 23.4-EVO | 23.4R1-EVO or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
An Improper Handling of Exceptional Conditions vulnerability in the routing protocol daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved allows a network based, unauthenticated attacker to cause the RPD process to crash leading to a Denial of Service (DoS).
When a malformed BGP UPDATE packet is received over an established BGP session, RPD crashes and restarts.
Continuous receipt of the malformed BGP UPDATE messages will create a sustained Denial of Service (DoS) condition for impacted devices.
This issue affects eBGP and iBGP, in both IPv4 and IPv6 implementations. This issue requires a remote attacker to have at least one established BGP session.
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-S6; * 22.1 versions earlier than 22.1R3-S4; * 22.2 versions earlier than 22.2R3-S3; * 22.3 versions earlier than 22.3R3-S2; * 22.4 versions earlier than 22.4R3; * 23.2 versions earlier than 23.2R2.
Juniper Networks Junos OS Evolved: * All versions earlier than 21.2R3-S7; * 21.3-EVO versions earlier than 21.3R3-S5; * 21.4-EVO versions earlier than 21.4R3-S8; * 22.1-EVO versions earlier than 22.1R3-S4; * 22.2-EVO versions earlier than 22.2R3-S3; * 22.3-EVO versions earlier than 22.3R3-S2; * 22.4-EVO versions earlier than 22.4R3; * 23.2-EVO versions earlier than 23.2R2.
Am I affected?
To be exposed to this issue the device needs to be configure for one established BGP session:
[ protocols bgp group <name> neighbor <address> ]
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.