NVD / CVE Program· CNA apache

CVE-2021-33035: Buffer overflow from a crafted DBF file

Noroxi assessment

Priority: Plan (action score 46/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 50.5% (FIRST EPSS); higher than 98.9% of all records.
Someone with local access to the system can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
Fixed version: libreoffice (Debian:12) 1:4.3.1-1.
Mentioned 3 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Add it to your regular patch cycle. Upgrade to libreoffice (Debian:12) 1:4.3.1-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Apache OpenOffice opens dBase/DBF documents and shows the contents as spreadsheets. DBF are database files with data organized in fields. When reading DBF data the size of certain fields is not checked: the data is just copied into local variables. A carefully crafted document could overflow the allocated space, leading to the execution of arbitrary code by altering the contents of the program stack. This issue affects Apache OpenOffice up to and including version 4.1.10

HighCVSS 7.8 · v3.1—No exploit Fix available

BDU:2021-04717

Published: Sep 23, 2021
Updated: Jun 16, 2026
EPSS: 50.5% · 98th percentile
CWE: CWE-120

Report tools

JSON

Action score

Plan

Add it to your regular patch cycle.

CVSS: 31 / 40 · 7.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 15 / 30 · 50.5%

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Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
apache	openoffice	cpe:2.3:a:apache:openoffice

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

apache openofficeup to 4.1.10 inclusive

Versions reported by the vendor

Affected version ranges reported by the assigning authority (apache). Independent of NVD's CPE analysis and usually ahead of it.

Apache Software Foundation Apache OpenOffice
- Apache OpenOffice and later · up to and including 4.1.10affected
- OpenOffice.org and later · up to and including 3.4affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:12	libreoffice	before 1:4.3.1-1	1:4.3.1-1

Same product

apache: all records

Other highest-scoring records for the same primary product.

CVE-2014-3524Apache OpenOffice before 4.1.1 allows remote attackers to execute arbitrary commands and possibly have other unspecified impact via a crafte
41Plan
CVE-2009-3302filter/ww8/ww8par2.cxx in OpenOffice.org (OOo) before 3.2 allows remote attackers to cause a denial of service (application crash) or possib
41Plan
CVE-2009-3301Integer underflow in filter/ww8/ww8par2.cxx in OpenOffice.org (OOo) before 3.2 allows remote attackers to cause a denial of service (applica
41Plan

Published before and after this one in the same product

← EarlierCVE-2020-13958Nov 17, 2020 · A vulnerability in Apache OpenOffice scripting events allows an attacker to construct documents containing hyperlinks pointing to an executa
32Monitor
← EarlierCVE-2021-30245Apr 15, 2021 · Code execution in Apache OpenOffice via non-http(s) schemes in Hyperlinks
36Monitor
Later →CVE-2021-28129Oct 7, 2021 · DEB packaging for Apache OpenOffice 4.1.8 installed with a non-root userid and groupid
31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
debian:libreoffice	1:4.3.1-1 · Debian:12	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

apache/openofficecommit efddaef

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-21-0826 · Oct 12, 2021(OpenOffice Güvenlik Zafiyeti)
TR-21-0775 · Sep 24, 2021(OpenOffice Güvenlik Güncellemesi)
TR-21-0769 · Sep 23, 2021(Apple Güvenlik Zafiyeti)

All national notices →

Technical details

Attack conditions

Someone with local access to the system can trigger it.
No account or password is required.
A user must open a link or visit a page.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Local
Attack complexity: Low
Privileges required: None
User interaction: Required
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-120 · Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

nvd-primary

Root cause

When data is copied, the source length is not compared with the size of the destination buffer. Excess data overwrites adjacent memory.

The bug in code

The whole CWE-120 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1char buf[256];
2memcpy(buf, pkt->data, pkt->len);

Fixed

1char buf[256];
2if (pkt->len > sizeof(buf)) {
3  return -EINVAL;
4}
5memcpy(buf, pkt->data, pkt->len);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

—

Change log

Fix✗ → ✓Sep 28, 2026, 10:48 PM UTC

For records you follow, these changes also arrive as notifications. →

References

www.openwall.com/lists/oss-security/2021/10/07/3

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records