CVE-2017-20004Public exploitNetwork attack vector

Memory-safety violation via unsound MutexGuard Sync bound

Published Apr 14, 2021 · Updated Aug 5, 2024

Race condition in the Rust standard library before 1.19.0 allows attackers to violate memory safety through concurrent MutexGuard access. MutexGuard incorrectly implements Sync when T is merely Send, exposing non-Sync interior-mutability types through shared guard references. Exploitation requires an affected program to share such a guard across threads, where unsynchronized reads and writes can corrupt protected data.

CVSS severity5.9
Medium
EPSS probability0.80%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in the Rust standard library before 1.19.0 allows attackers to violate memory safety through concurrent MutexGuard access. MutexGuard incorrectly implements Sync when T is merely Send, exposing non-Sync interior-mutability types through shared guard references. Exploitation requires an affected program to share such a guard across threads, where unsynchronized reads and writes can corrupt protected data.

The record

CVE
CVE-2017-20004
Published
Apr 14, 2021
Updated
Aug 5, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-362
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 14, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.9NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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