CVE-2020-11536Network attack vector

Remote code execution via crafted DOCX extraction

Published Apr 15, 2020 · Updated Aug 4, 2024

Improper input validation in x2t in ONLYOFFICE Document Server 5.5.0 allows remote attackers to execute code via a crafted DOCX file. The x2t unzip function processes attacker-controlled archive content and can overwrite a server binary with an extracted file. Exploitation requires Document Server to process the malicious document, after which the replaced binary runs code on the server host.

CVSS severity9.8
Critical
EPSS probability2.59%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in x2t in ONLYOFFICE Document Server 5.5.0 allows remote attackers to execute code via a crafted DOCX file. The x2t unzip function processes attacker-controlled archive content and can overwrite a server binary with an extracted file. Exploitation requires Document Server to process the malicious document, after which the replaced binary runs code on the server host.

The record

CVE
CVE-2020-11536
Published
Apr 15, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-20, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 15, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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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