CVE-2021-45695

Code execution via assumed trait-object layout

Published Dec 26, 2021 · Updated Aug 4, 2024

Memory unsoundness in mopa 0.2.2 and earlier allows attackers to expose ASLR addresses or execute code after a trait-layout change. Its downcasting methods transmute trait-object references into a hand-defined structure and treat the resulting fields as data and vtable pointers, although Rust does not guarantee that layout. Exploitation requires a compiler that changes the assumed field order and a consuming application path that performs an affected downcast; Rust 1.52 retained the assumed layout.

CVSS severity9.8
Critical
EPSS probability1.65%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory unsoundness in mopa 0.2.2 and earlier allows attackers to expose ASLR addresses or execute code after a trait-layout change. Its downcasting methods transmute trait-object references into a hand-defined structure and treat the resulting fields as data and vtable pointers, although Rust does not guarantee that layout. Exploitation requires a compiler that changes the assumed field order and a consuming application path that performs an affected downcast; Rust 1.52 retained the assumed layout.

The record

CVE
CVE-2021-45695
Published
Dec 26, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
Unavailable
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

9.8GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/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

No sourced classifications are available.

Public exploit references

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Technologies

Your stack

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Your stack

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