CVE-2021-45704

Memory corruption via unchecked Send and Sync bounds

Published Dec 26, 2021 · Updated Aug 4, 2024

Memory corruption in the metrics-util crate before 0.7.0 allows attackers to trigger a data race through AtomicBucket::data_with(). AtomicBucket's internal Block implements Send and Sync without requiring T to satisfy the corresponding trait bound, so data_with() can expose a non-Sync value across threads. Exploitation requires application code to place a non-Sync value in an AtomicBucket and invoke the API concurrently, producing undefined behavior that can corrupt memory.

CVSS severity8.1
High
EPSS probability0.74%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory corruption in the metrics-util crate before 0.7.0 allows attackers to trigger a data race through AtomicBucket::data_with(). AtomicBucket's internal Block implements Send and Sync without requiring T to satisfy the corresponding trait bound, so data_with() can expose a non-Sync value across threads. Exploitation requires application code to place a non-Sync value in an AtomicBucket and invoke the API concurrently, producing undefined behavior that can corrupt memory.

The record

CVE
CVE-2021-45704
Published
Dec 26, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, CWE-362
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Dec 26, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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 vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.8National Vulnerability DatabaseAV:N/AC:M/Au:N/C:P/I:P/A:P
8.1National Vulnerability DatabaseCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

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)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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