CVE intelligence and bounded remediation

CVE-2024-30391 — Juniper Junos security vulnerability

Medium CVSS 6.3

A Missing Authentication for Critical Function vulnerability in the Packet Forwarding Engine (pfe) of Juniper Networks Junos OS on MX Series with SPC3, and SRX Series allows an unauthenticated network-based attacker to cause limited impact to the integrity or availability of the device. If a device is configured with IPsec authentication algorithm hmac-sha-384 or hmac-sha-512, tunnels are established normally but for traffic traversing the tunnel no authentication information is sent with the encrypted data on egress, and no authentication information is expected on ingress. So if the peer is an unaffected device transit traffic is going to fail in both directions. If the peer is an also affected device transit traffic works, but without authentication, and configuration and CLI operational commands indicate authentication is performed. This issue affects Junos OS: * All versions before 20.4R3-S7, * 21.1 versions before 21.1R3, * 21.2 versions before 21.2R2-S1, 21.2R3, * 21.3 versions before 21.3R1-S2, 21.3R2.

Severity
Medium
CVSS
6.3 (4.0)
Published
2024-04-12
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-306

Affected products

  • juniper / junos
  • juniper / junos / 20.4

Showing 2 representative product identities from 28 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Authentication bypass and missing authentication

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Map every affected endpoint and protocol path, including alternate ports, legacy routes, recovery flows, service accounts, and machine-to-machine access.
  • Confirm which deployments enable the affected authentication mode and whether the interface is reachable from untrusted networks.
  • Review session, token, credential, and proxy trust configuration without attempting account takeover.

Remediate safely

  • Apply the supported fix and centralize fail-closed authentication before protected request handling.
  • Remove default or embedded credentials, rotate affected secrets and sessions, and bind authentication decisions to the intended audience and channel.
  • Add negative tests for alternate routes, malformed or absent credentials, recovery flows, and proxy-derived identity.

Authoritative sources

Complete CVE record and remediation plan

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