Improper neutralization of equivalent special elements in Juniper Junos OS

1) Improper neutralization of equivalent special elements

EUVDB-ID: #VU85275

Risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2024-21600

CWE-ID: CWE-76 - Improper Neutralization of Equivalent Special Elements

Exploit availability: No

Description

The vulnerability allows a remote non-authenticated attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to improper neutralization of equivalent special elements error in the Packet Forwarding Engine (PFE). A remote non-authenticated attacker can cause a Denial of Service (DoS).

When MPLS packets are meant to be sent to a flexible tunnel interface (FTI) and if the FTI tunnel is down, these will hit the reject NH, due to which the packets get sent to the CPU and cause a host path wedge condition.

This will cause the FPC to hang and requires a manual restart to recover.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Juniper Junos OS: 20.4R1 - 22.3R1-S2

External links

http://supportportal.juniper.net/s/article/2024-01-Security-Bulletin-Junos-OS-PTX-Series-In-an-FTI-scenario-MPLS-packets-hitting-reject-next-hop-will-cause-a-host-path-wedge-condition-CVE-2024-21600

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.