CVE-2021-1715

Code execution via DOC parser out-of-bounds write

Published Jan 12, 2021 · Updated Oct 8, 2024

Out-of-bounds write in Microsoft Word allows remote attackers to execute code by convincing a user to open a crafted DOC file. The DOC parser insufficiently validates user-supplied data before writing beyond the end of an allocated buffer. Exploitation requires the target to visit a malicious page or open the file and runs code in the current process context.

CVSS severity7.8
High
EPSS probability3.60%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in Microsoft Word allows remote attackers to execute code by convincing a user to open a crafted DOC file. The DOC parser insufficiently validates user-supplied data before writing beyond the end of an allocated buffer. Exploitation requires the target to visit a malicious page or open the file and runs code in the current process context.

The record

CVE
CVE-2021-1715
Published
Jan 12, 2021
Updated
Oct 8, 2024
Vendor
Microsoft
Product
Microsoft Office 2019
Classifications
CWE-787, T1204.002, T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 12, 2021CVE publishedPublication date reported by the CVE source.
  2. Oct 8, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=19.0.0 <https://aka.ms/OfficeSecurityReleases

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Microsoft · Microsoft Office 2019version=19.0.0 <https://aka.ms/OfficeSecurityReleases
Microsoft · Microsoft SharePoint Enterprise Server 2016version=16.0.0 <publication
Microsoft · Microsoft SharePoint Server 2010version=13.0.0.0 <publication
Microsoft · Microsoft SharePoint Enterprise Server 2013version=15.0.0 <publication
Microsoft · Microsoft SharePoint Server 2019version=16.0.0 <publication
Microsoft · Microsoft Office 2019 for Macversion=16.0.0 <publication
Microsoft · Microsoft Office Web Apps 2010version=13.0.0 <publication
Microsoft · Microsoft Office Online Serverversion=16.0.1 <publication
Microsoft · Microsoft Word 2013version=15.0.1 <publication
Microsoft · Microsoft Word 2016version=16.0.1 <publication
Microsoft · Microsoft Office Web Apps Server 2013version=15.0.1 <publication
Microsoft · Microsoft Office 2010version=13.0.0.0 <publication
Microsoft · Microsoft Word 2010version=13.0.0.0 <publication
Microsoft · Microsoft 365 Apps for enterpriseversion=16.0.1 <https://aka.ms/OfficeSecurityReleases

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
9.3NIST NVDAV:N/AC:M/Au:N/C:C/I:C/A:C

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1204.002User Execution: Malicious File
T1203Exploitation for Client Execution

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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