CVE-2020-36433Public exploitNetwork attack vector

Undefined behavior via unaligned Chunk references

Published Aug 8, 2021 · Updated Aug 4, 2024

Memory-safety flaws in chunky 0.3.7 and earlier allow attackers to trigger undefined behavior through the Chunk API. Value::deref and Value::deref_mut cast a Chunk buffer pointer to V and create references without satisfying V’s alignment requirement. Triggering the flaw requires a consuming application to store a type whose alignment exceeds the backing allocation; the invalid reference leaves program behavior undefined.

CVSS severity7.5
High
EPSS probability0.92%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory-safety flaws in chunky 0.3.7 and earlier allow attackers to trigger undefined behavior through the Chunk API. Value::deref and Value::deref_mut cast a Chunk buffer pointer to V and create references without satisfying V’s alignment requirement. Triggering the flaw requires a consuming application to store a type whose alignment exceeds the backing allocation; the invalid reference leaves program behavior undefined.

The record

CVE
CVE-2020-36433
Published
Aug 8, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-758
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 8, 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 vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.0NIST National Vulnerability DatabaseAV:N/AC:L/Au:N/C:N/I:P/A:N
7.5GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
7.5NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
7.5RustSec Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-758Reliance on Undefined, Unspecified, or Implementation-Defined Behavior

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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