CVE-2021-32263Public exploit

Memory corruption via oversized circular-buffer copy

Published Aug 24, 2021 · Updated Aug 3, 2024

Heap-based buffer overflow in ok-file-formats through 2021-04-29 allows attackers to corrupt memory by parsing a crafted CSV file. On the demonstrated path, ok_csv_circular_buffer_read writes 181 CSV-derived bytes into a 64-byte heap allocation without limiting the write to the remaining capacity. A consuming application must parse the crafted file; the published reproducer triggers an AddressSanitizer abort, while code execution remains unproven.

CVSS severity7.8
High
EPSS probability0.87%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflow in ok-file-formats through 2021-04-29 allows attackers to corrupt memory by parsing a crafted CSV file. On the demonstrated path, ok_csv_circular_buffer_read writes 181 CSV-derived bytes into a 64-byte heap allocation without limiting the write to the remaining capacity. A consuming application must parse the crafted file; the published reproducer triggers an AddressSanitizer abort, while code execution remains unproven.

The record

CVE
CVE-2021-32263
Published
Aug 24, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 24, 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 vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.8NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.8NVDAV:N/AC:M/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)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1204.002Malicious File

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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