An Improper Handling of Exceptional Conditions vulnerability in the packet forwarding engine (PFE) of Juniper Networks Junos OS on SRX Series allows an unauthenticated network-based attacker sending a specific ICMP packet through a GRE tunnel to cause the PFE to crash and restart.
When PowerMode IPsec (PMI) and GRE performance acceleration are enabled and the device receives a specific ICMP packet, a crash occurs in the SRX PFE, resulting in traffic loss. PMI is enabled by default, and GRE performance acceleration can be enabled by running the configuration command shown below. PMI is a mode of operation that provides IPsec performance improvements using Vector Packet Processing.
Note that PMI with GRE performance acceleration is only supported on specific SRX platforms. This issue affects Junos OS on the SRX Series:
| Software | From | Fixed in |
|---|---|---|
| juniper / junos | - | 21.4 |
| juniper / junos | 21.4 | 21.4.x |
| juniper / junos | 21.4-r1 | 21.4-r1.x |
| juniper / junos | 21.4-r1-s1 | 21.4-r1-s1.x |
| juniper / junos | 21.4-r1-s2 | 21.4-r1-s2.x |
| juniper / junos | 21.4-r2 | 21.4-r2.x |
| juniper / junos | 21.4-r2-s1 | 21.4-r2-s1.x |
| juniper / junos | 21.4-r2-s2 | 21.4-r2-s2.x |
| juniper / junos | 21.4-r3 | 21.4-r3.x |
| juniper / junos | 21.4-r3-s1 | 21.4-r3-s1.x |
| juniper / junos | 21.4-r3-s10 | 21.4-r3-s10.x |
| juniper / junos | 21.4-r3-s11 | 21.4-r3-s11.x |
| juniper / junos | 21.4-r3-s2 | 21.4-r3-s2.x |
| juniper / junos | 21.4-r3-s3 | 21.4-r3-s3.x |
| juniper / junos | 21.4-r3-s4 | 21.4-r3-s4.x |
| juniper / junos | 21.4-r3-s5 | 21.4-r3-s5.x |
| juniper / junos | 21.4-r3-s6 | 21.4-r3-s6.x |
| juniper / junos | 21.4-r3-s7 | 21.4-r3-s7.x |
| juniper / junos | 21.4-r3-s8 | 21.4-r3-s8.x |
| juniper / junos | 21.4-r3-s9 | 21.4-r3-s9.x |
| juniper / junos | 22.4 | 22.4.x |
| juniper / junos | 22.4-r1 | 22.4-r1.x |
| juniper / junos | 22.4-r1-s1 | 22.4-r1-s1.x |
| juniper / junos | 22.4-r1-s2 | 22.4-r1-s2.x |
| juniper / junos | 22.4-r2 | 22.4-r2.x |
| juniper / junos | 22.4-r2-s1 | 22.4-r2-s1.x |
| juniper / junos | 22.4-r2-s2 | 22.4-r2-s2.x |
| juniper / junos | 22.4-r3 | 22.4-r3.x |
| juniper / junos | 22.4-r3-s1 | 22.4-r3-s1.x |
| juniper / junos | 22.4-r3-s2 | 22.4-r3-s2.x |
| juniper / junos | 22.4-r3-s3 | 22.4-r3-s3.x |
| juniper / junos | 22.4-r3-s4 | 22.4-r3-s4.x |
| juniper / junos | 22.4-r3-s5 | 22.4-r3-s5.x |
| juniper / junos | 22.4-r3-s6 | 22.4-r3-s6.x |
| juniper / junos | 22.4-r3-s7 | 22.4-r3-s7.x |
| juniper / junos | 23.2 | 23.2.x |
| juniper / junos | 23.2-r1 | 23.2-r1.x |
| juniper / junos | 23.2-r1-s1 | 23.2-r1-s1.x |
| juniper / junos | 23.2-r1-s2 | 23.2-r1-s2.x |
| juniper / junos | 23.2-r2 | 23.2-r2.x |
| juniper / junos | 23.2-r2-s1 | 23.2-r2-s1.x |
| juniper / junos | 23.2-r2-s2 | 23.2-r2-s2.x |
| juniper / junos | 23.2-r2-s3 | 23.2-r2-s3.x |
| juniper / junos | 23.2-r2-s4 | 23.2-r2-s4.x |
| juniper / junos | 23.4 | 23.4.x |
| juniper / junos | 23.4-r1 | 23.4-r1.x |
| juniper / junos | 23.4-r1-s1 | 23.4-r1-s1.x |
| juniper / junos | 23.4-r1-s2 | 23.4-r1-s2.x |
| juniper / junos | 23.4-r2 | 23.4-r2.x |
| juniper / junos | 23.4-r2-s1 | 23.4-r2-s1.x |
| juniper / junos | 23.4-r2-s2 | 23.4-r2-s2.x |
| juniper / junos | 23.4-r2-s3 | 23.4-r2-s3.x |
| juniper / junos | 23.4-r2-s4 | 23.4-r2-s4.x |
| juniper / junos | 24.2 | 24.2.x |
| juniper / junos | 24.2-r1 | 24.2-r1.x |
| juniper / junos | 24.2-r1-s1 | 24.2-r1-s1.x |
| juniper / junos | 24.2-r1-s2 | 24.2-r1-s2.x |
| juniper / junos | 24.2-r2 | 24.2-r2.x |
| juniper / junos | 24.2-r2-s1 | 24.2-r2-s1.x |
| juniper / junos | 24.2-r2-s2 | 24.2-r2-s2.x |
| juniper / junos | 24.4 | 24.4.x |
| juniper / junos | 24.4-r1 | 24.4-r1.x |
| juniper / junos | 24.4-r1-s2 | 24.4-r1-s2.x |
| juniper / junos | 24.4-r1-s3 | 24.4-r1-s3.x |
| juniper / junos | 24.4-r2 | 24.4-r2.x |
| juniper / junos | 25.2 | 25.2.x |
| juniper / junos | 25.2-r1 | 25.2-r1.x |
| juniper / junos | 25.2-r2 | 25.2-r2.x |
A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.
CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.
A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.
Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.
Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.
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