Juniper Junos OS: 2025-04 Security Bulletin: Junos OS: MX Series: Decapsulation of specific GRE packets leads to PFE reset (JSA96471) (CVE-2025-30660)

An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (pfe) of Juniper Networks Junos OS on MX Series allows an unauthenticated, network-based attacker to 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:

<fpc #> MQSS(0): LI-3: Received a parcel with more than 512B accompanying data
CHASSISD_FPC_ASIC_ERROR: ASIC Error detected <...>

This issue affects Junos OS:

* all versions before 21.2R3-S9,
* 21.4 versions before 21.4R3-S8,
* 22.2 versions before 22.2R3-S4,
* 22.4 versions before 22.4R3-S5,
* 23.2 versions before 23.2R2-S2,
* 23.4 versions before 23.4R2.