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CVE-2021-40439· NVD / CVE Program· CNA apache

Apache OpenOffice has a dependency on expat software.

Apache OpenOffice has a dependency on expat software. Versions prior to 2.1.0 were subject to CVE-2013-0340 a "Billion Laughs" entity expansion denial of service attack and exploit via crafted XML files. ODF files consist of a set of XML files. All versions of Apache OpenOffice up to 4.1.10 are subject to this issue. expat in version 4.1.11 is patched.

MediumCVSS 6.5 · v3.1—No exploit No fix recorded
Published
Oct 7, 2021
Updated
Jun 17, 2026
EPSS
3.9% · 90th percentile
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Report tools

JSON

Action score

27

Monitor

Low priority for now.

CVSS
26 / 40 · 6.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 3.9%

Noroxi analysis

No Noroxi analysis for this record yet

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Affected systems

VendorProduct
apacheopenoffice

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

Same product

apache: all records

Other highest-scoring records for the same primary product.

  • CVE-2021-33035Buffer overflow from a crafted DBF file
    46Plan
  • 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
  • CVE-2009-2950Heap-based buffer overflow in the GIFLZWDecompressor::GIFLZWDecompressor function in filter.vcl/lgif/decode.cxx in OpenOffice.org (OOo) befo
    41Plan
  • CVE-2009-2949Integer overflow in the XPMReader::ReadXPM function in filter.vcl/ixpm/svt_xpmread.cxx in OpenOffice.org (OOo) before 3.2 allows remote atta
    41Plan

Remediation

Which version to upgrade to

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

No fix version is recorded for this entry. Check the references for vendor advisories.

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.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

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

No commit or PR link among the references.

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).

Technical details

Attack conditions

  • Anyone who can reach it over the internet 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
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-611 · Improper Restriction of XML External Entity Reference

CVSS vector

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

nvd-primary

Attack context

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

ATT&CK techniques

—

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

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

All records