CVE-2024-39555 Junos OS and Junos OS Evolved: Receipt of a specific malformed BGP update causes the session to reset
Remote attackers can cause a sustained denial of service by sending malformed BGP updates to Juniper devices with segment routing enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2024-39555?
CVE-2024-39555 is a high-severity denial of service vulnerability in Juniper Junos, published on 10 Jul 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
An Improper Handling of Exceptional Conditions vulnerability in the Routing Protocol Daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved allows an attacker sending a specific malformed BGP update message to cause the session to reset, resulting in a Denial of Service (DoS). Continued receipt and processing of these malformed BGP update messages will create a sustained Denial of Service (DoS) condition.
Upon receipt of a BGP update message over an established BGP session containing a specifically malformed tunnel encapsulation attribute, when segment routing is enabled, internal processing of the malformed attributes within the update results in improper parsing of remaining attributes, leading to session reset:
BGP SEND Notification code 3 (Update Message Error) subcode 1 (invalid attribute list)
Only systems with segment routing enabled are vulnerable to this issue.
This issue affects eBGP and iBGP, in both IPv4 and IPv6 implementations, and requires a remote attacker to have at least one established BGP session.
This issue affects:
Junos OS:
* All versions before 21.4R3-S8, * from 22.2 before 22.2R3-S4, * from 22.3 before 22.3R3-S3, * from 22.4 before 22.4R3-S3, * from 23.2 before 23.2R2-S1, * from 23.4 before 23.4R1-S2, 23.4R2.
Junos OS Evolved:
* All versions before 21.4R3-S8-EVO, * from 22.2-EVO before 22.2R3-S4-EVO, * from 22.3-EVO before 22.3R3-S3-EVO, * from 22.4-EVO before 22.4R3-S3-EVO, * from 23.2-EVO before 23.2R2-S1-EVO, * from 23.4-EVO before 23.4R1-S2-EVO, 23.4R2-EVO.
Weakness: CWE-755
Which versions are affected by CVE-2024-39555?
It affects 2 products.
Products include Juniper Junos, Juniper Junos Os Evolved.
How do I fix CVE-2024-39555?
No fix has been published for CVE-2024-39555 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2024-39555 being exploited?
There is no known exploitation of CVE-2024-39555 in the wild and no public exploit code.
Other vulnerabilities in Juniper Junos
- CVE-2023-36845 Juniper Junos OS EX Series and SRX Series PHP External Variable Modification
- CVE-2020-1631 Juniper Junos OS Path Traversal
- CVE-2025-21590 Juniper Junos OS Improper Isolation or Compartmentalization
- CVE-2023-36851 Juniper Junos OS SRX Series Missing Authentication for Critical Function
- CVE-2023-36844 Juniper Junos OS EX Series PHP External Variable Modification
Sources
Also known as GHSA-93cc-g9p8-jrr7.