CVE intelligence and bounded remediation

CVE-2021-40439 — Apache OpenOffice has a dependency on expat software

Medium CVSS 6.5

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.

Severity
Medium
CVSS
6.5 (3.1)
Published
2021-10-07
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-611

Affected products

  • apache / openoffice

Matched remediation archetype

XML external entity and unsafe XML processing

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Inventory XML parsers used by APIs, file imports, office or image formats, identity protocols, feeds, and background jobs.
  • Determine whether document type declarations, external entities, XInclude, schemas, or network resolvers are enabled.
  • Map parser filesystem and network access and the sensitivity of documents it processes.

Remediate safely

  • Configure each parser to reject document type declarations and disable external entity, XInclude, and network resolution features.
  • Prefer a data format or hardened parser that does not support external resolution, and apply input size and depth limits.
  • Update affected XML libraries and centralize secure parser construction so callers cannot silently override it.

Authoritative sources

Complete CVE record and remediation plan

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