CVE-2021-30456

Memory corruption via panic-triggered double free

Published Apr 7, 2021 · Updated Aug 3, 2024

Double free in id-map through 2021-02-26 allows attackers to corrupt process memory by triggering a panic in a supplied closure. The get_or_insert method reserves a slot before calling f, so a panic causes the map to drop uninitialized or previously freed memory. Reachability requires consuming code to call get_or_insert with a fallible user-supplied closure; a resulting panic can crash the process or corrupt its memory.

CVSS severity9.8
Critical
EPSS probability1.10%
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 id-map through 2021-02-26 allows attackers to corrupt process memory by triggering a panic in a supplied closure. The get_or_insert method reserves a slot before calling f, so a panic causes the map to drop uninitialized or previously freed memory. Reachability requires consuming code to call get_or_insert with a fallible user-supplied closure; a resulting panic can crash the process or corrupt its memory.

The record

CVE
CVE-2021-30456
Published
Apr 7, 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 7, 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

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P

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-415Double Free

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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