CVE-2021-20839

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-11-01 · updated 2026-06-17
Weakness: CWE-611

Description

Office Server Document Converter V7.2MR4 and earlier and V7.1MR7 and earlier allows a remote unauthenticated attacker to conduct an XML External Entity (XXE) attack to cause a denial of service (DoS) condition to the other servers by processing a specially crafted XML document.

Affected products

Antenna House, Inc. Office Server Document Converter: before 5.2; 5.2, 6.0, 6.0-mr1, 6.0-mr2, 6.1, 6.1-mr2 (+15) — fixed in 5.2

How to fix

Upgrade to a fixed version: Antenna House, Inc. Office Server Document Converter 5.2. Check the vendor advisory for mitigations.

References

https://jvn.jp/en/jp/JVN33453839/index.html
https://www.antenna.co.jp/news/2021/osdc72-20211027.html
https://jvn.jp/en/jp/JVN33453839/index.html
https://www.antenna.co.jp/news/2021/osdc72-20211027.html

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