Auth bypass in Juniper Csrx

CVE-2024-30391

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.

Vulnerability class: Broken Authentication

EPSS: 0.004 (37.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2024-30391?
CVE-2024-30391 is a medium-severity vulnerability in Juniper Csrx, classified under Missing Authentication for Critical Function. CVSS score: 4.8/10. Published 2024-04-12.
How severe is CVE-2024-30391?
Medium severity. CVSS v3 base score is 4.8 out of 10.
Is CVE-2024-30391 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.