CVE-2021-38191

Exp

An issue was discovered in the tokio crate before 1.8.1 for Rust. Upon a JoinHandle::abort, a Task may be dropped in the wrong thread.

Published: 2021-08-08 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-38191 is rated Exploit Available (57.5/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.83%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2021-38191

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-38191

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.34% 0.83% +0.49%
2 2026-02-21 0.24% 0.34% +0.10%
3 2025-03-30 — 0.24% —

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-38191

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.2 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2021-38191

GitHub Security Advisory for CVE-2021-38191

OS Trackers for CVE-2021-38191

vendor priority summary link
debian unimportant CVE-2021-38191 unimportant priority: Debian including 1 source packages (rust-tokio), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-38191
ubuntu medium CVE-2021-38191 medium priority: Ubuntu including 1 source packages (rust-tokio), 8 status rows across 8 suites (bionic, focal, hirsute, impish, jammy, trusty, upstream, xenial): not-affected 5, DNE 2, ignored 1. https://ubuntu.com/security/CVE-2021-38191

Affected software / configurations for CVE-2021-38191

Vendor Product Version Raw CPE
tokio tokio >= 0.3.0, < 1.5.1 cpe:2.3:a:tokio:tokio:*:*:*:*:*:rust:*:*
tokio tokio >= 1.6.0, < 1.6.3 cpe:2.3:a:tokio:tokio:*:*:*:*:*:rust:*:*
tokio tokio >= 1.7.0, < 1.7.2 cpe:2.3:a:tokio:tokio:*:*:*:*:*:rust:*:*
tokio tokio 1.8.0 cpe:2.3:a:tokio:tokio:1.8.0:*:*:*:*:*:*:*

References for CVE-2021-38191

cvelogic Threat Intelligence