#VU107435 Improper check for unusual or exceptional conditions in Juniper Junos OS - CVE-2025-30660

Vulnerability identifier: #VU107435

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2025-30660

CWE-ID: CWE-754

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Juniper Junos OS
Operating systems & Components / Operating system

Vendor: Juniper Networks, Inc.

Description

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

The vulnerability exists due to improper check for unusual or exceptional conditions error in the Packet Forwarding Engine (pfe). A remote non-authenticated attacker can cause a Denial-of-Service (DoS).

 When processing a high rate of specific GRE traffic destined to the device, the respective PFE will hang causing traffic forwarding to stop.

 When this issue occurs the following logs can be observed: MQSS(0): LI-3: Received a parcel with more than 512B accompanying dataCHASSISD_FPC_ASIC_ERROR: ASIC Error detected.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Juniper Junos OS: before 21.2R3-S9, 21.4R3-S8, 22.2R3-S4, 22.4R3-S5, 23.2R2-S2, 23.4R2, 24.2R1, 21.2R3-S9, 21.2R3-S9, 21.2R3-S9, 21.2R3-S9, 21.2R3-S9, 21.2R3-S9, 21.2R3-S9

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External links
https://supportportal.juniper.net/s/article/2025-04-Security-Bulletin-Junos-OS-MX-Series-Decapsulation-of-specific-GRE-packets-leads-to-PFE-reset-CVE-2025-30660

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

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