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
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
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
Impact
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. This also applies if reject_remote_clients is not explicitly set as this is the default configuration and is cleared by calling pipe_mode.
Remote clients may only access the named pipe if the named pipe's associated path is accessible via a publically shared folder (SMB).
Patches
The following versions have been patched:
- 1.23.1
- 1.20.3
- 1.18.4
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.
Workarounds
Ensure that pipe_mode is set first after initializing a ServerOptions. For example:
let mut opts = ServerOptions::new();
opts.pipe_mode(PipeMode::Message);
opts.reject_remote_clients(true);
References
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 |
Affected Products
tokiotokioDetection & 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.
Frequently Asked Questions
Is CVE-2023-22466 in your dependencies?
Find it across crates.io, including transitive dependencies.