CVE-2021-33035Public exploit

Code execution via unchecked DBF field length

Published Sep 23, 2021 · Updated Aug 3, 2024

Classic buffer overflow in Apache OpenOffice 4.1.10 and earlier allows attackers to execute arbitrary code via a crafted DBF document. ODbaseTable::fetchRow copies attacker-controlled nLen bytes from DBF integer fields into a four-byte sal_Int32 local without validating the field length. The attack requires a user to open the document; successful exploitation overwrites the program stack and executes code in that user's context.

CVSS severity7.8
High
EPSS probability50.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Classic buffer overflow in Apache OpenOffice 4.1.10 and earlier allows attackers to execute arbitrary code via a crafted DBF document. ODbaseTable::fetchRow copies attacker-controlled nLen bytes from DBF integer fields into a four-byte sal_Int32 local without validating the field length. The attack requires a user to open the document; successful exploitation overwrites the program stack and executes code in that user's context.

The record

CVE
CVE-2021-33035
Published
Sep 23, 2021
Updated
Aug 3, 2024
Vendor
The Apache Software Foundation
Product
Apache OpenOffice
Classifications
CWE-120, T1204.002, T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 23, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Apache OpenOffice <=4.1.10
  2. Affected versionversion=OpenOffice.org <=3.4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache OpenOfficeversion=Apache OpenOffice <=4.1.10; version=OpenOffice.org <=3.4

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.8NIST NVDAV: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.

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)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1204.002Malicious File
T1203Exploitation for Client Execution

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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