CVE-2021-29933Public exploit

Process crash via panic-triggered double drop

Published Apr 1, 2021 · Updated Aug 3, 2024

Double free in the insert_many Rust crate 0.1.1 and earlier allows context-dependent attackers to crash a process through a panicking iterator. The impl_veclike! macro uses ptr::copy to shift vector elements, duplicating ownership before it calls Iterator::next without guarding unwinding. Code must pass an ExactSizeIterator whose next method panics; unwinding then drops copied elements twice, corrupting memory and terminating the process.

CVSS severity7.5
High
EPSS probability1.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Double free in the insert_many Rust crate 0.1.1 and earlier allows context-dependent attackers to crash a process through a panicking iterator. The impl_veclike! macro uses ptr::copy to shift vector elements, duplicating ownership before it calls Iterator::next without guarding unwinding. Code must pass an ExactSizeIterator whose next method panics; unwinding then drops copied elements twice, corrupting memory and terminating the process.

The record

CVE
CVE-2021-29933
Published
Apr 1, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-415
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Apr 1, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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

7.5RustSec Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-415Double Free

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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