Junos OS (SRX firewalls)
CVE-2024-30391: MX Series with SPC3, and SRX Series: When IPsec authentication is configured with "hmac-sha-384" and "hmac-sha-512" no authentication of traffic is performed
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.
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| Junos OS (SRX Series, MX Series with SPC3) 0 | 20.4R3-S7 or later |
| Junos OS (SRX Series, MX Series with SPC3) 21.1 | 21.1R3 or later |
| Junos OS (SRX Series, MX Series with SPC3) 21.2 | 21.2R2-S1, 21.2R3 or later |
| Junos OS (SRX Series, MX Series with SPC3) 21.3 | 21.3R1-S2, 21.3R2 or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
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.
Am I affected?
For a device to be affected IPsec must be configured with either hmac-sha-384 or hmac-sha-512 as follows:
[ security ipsec proposal <proposal> authentication-algorithm hmac-sha-384/hmac-sha-512 ]
Workarounds
There are no known workarounds for this issue.
Exploitation
Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 13 Oct 2026.