CVE-2023-22466 is a medium-severity (CVSS 5.4) CWE-665 vulnerability in tokio. A fix is available for tokio — see the affected versions and patch details below.
Tokio's reject_remote_clients configuration may get dropped when creating a Windows named pipe
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-22466.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2023-22466 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
tokio🦀tokio🦀tokioReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
Tokio is a runtime for writing applications with Rust. Starting with version 1.7.0 and prior to versions 1.18.4, 1.20.3, and 1.23.1, when configuring a Windows named pipe server, setting pipe_mode will reset reject_remote_clients to false. If the application has previously configured reject_remote_clients to true, this effectively undoes the configuration. Remote clients may only access the named pipe if the named pipe's associated path is accessible via a publicly shared folder (SMB). Versions 1.23.1, 1.20.3, and 1.18.4 have been patched. The fix will also be present in all releases starting from version 1.24.0. Named pipes were introduced to Tokio in version 1.7.0, so releases older than 1.7.0 are not affected. As a workaround, ensure that pipe_mode is set first after initializing a ServerOptions.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | tokio | ≥ 1.7.0&&< 1.18.4 | 1.18.4cargo update -p tokio --precise 1.18.4 |
| 🦀crates.io | tokio | ≥ 1.19.0&&< 1.20.3 | 1.20.3cargo update -p tokio --precise 1.20.3 |
| 🦀crates.io | tokio | ≥ 1.21.0&&< 1.23.1 | 1.23.1cargo update -p tokio --precise 1.23.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tokio, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update tokio to 1.18.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-22466 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2023-22466 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-22466. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-22466 in your dependencies?
O3 Security finds CVE-2023-22466 across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.