CVE-2024-39526 Denial of service in Junos OS
Attackers can cause a denial of service by sending malformed DHCP packets to Juniper devices with DHCP snooping enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2024-39526?
CVE-2024-39526 is a high-severity denial of service vulnerability in Juniper Junos, published on 11 Oct 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
An Improper Handling of Exceptional Conditions vulnerability in packet processing of Juniper Networks Junos OS on MX Series with MPC10/MPC11/LC9600 line cards, EX9200 with EX9200-15C lines cards, MX304 devices, and Juniper Networks Junos OS Evolved on PTX Series, allows an attacker sending malformed DHCP packets to cause ingress packet processing to stop, leading to a Denial of Service (DoS). Continued receipt and processing of these packets will create a sustained Denial of Service (DoS) condition.
This issue only occurs if DHCP snooping is enabled. See configuration below.
This issue can be detected using following commands. Their output will display the interface status going down:
user@device>show interfaces <if--x/x/x> user@device>show log messages | match <if--x/x/x> user@device>show log messages ==> will display the "[Error] Wedge-Detect : Host Loopback Wedge Detected: PFE: no," logs.
This issue affects: Junos OS on
MX Series
with MPC10/MPC11/LC9600 line cards, EX9200 with EX9200-15C line cards, and MX304:
* All versions before 21.2R3-S7, * from 21.4 before 21.4R3-S6, * from 22.2 before 22.2R3-S3, * all versions of 22.3, * from 22.4 before 22.4R3, * from 23.2 before 23.2R2;
Junos OS Evolved on PTX Series: * from 19.3R1-EVO before 21.2R3-S8-EVO,
* from 21.4-EVO before 21.4R3-S7-EVO, * from 22.1-EVO before 22.1R3-S6-EVO, * from 22.2-EVO before 22.2R3-S5-EVO, * from 22.3-EVO before 22.3R3-S3-EVO, * from 22.4-EVO before 22.4R3-S1-EVO, * from 23.2-EVO before 23.2R2-S2-EVO, * from 23.4-EVO before 23.4R2-EVO.
Junos OS Evolved releases prior to 19.3R1-EVO are unaffected by this vulnerability
Weakness: CWE-755
Which versions are affected by CVE-2024-39526?
It affects 2 products.
Products include Juniper Junos, Juniper Junos Os Evolved.
How do I fix CVE-2024-39526?
No fix has been published for CVE-2024-39526 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-2024-39526 being exploited?
There is no known exploitation of CVE-2024-39526 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-qxf5-vpwf-vj9q.