CVE-2020-0979Network attack vector

User-assisted code execution via crafted spreadsheet file

Published Apr 15, 2020 · Updated Aug 4, 2024

Memory corruption in Microsoft Excel in Microsoft 365 Apps for enterprise allows remote attackers to execute code through a crafted file. Excel mishandles objects in memory while processing the file, but Microsoft has not disclosed the affected parser, object type, or invalid memory operation. Exploitation requires user interaction with attacker-controlled content, and successful code runs with the current user's privileges.

CVSS severity8.8
High
EPSS probability11.54%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory corruption in Microsoft Excel in Microsoft 365 Apps for enterprise allows remote attackers to execute code through a crafted file. Excel mishandles objects in memory while processing the file, but Microsoft has not disclosed the affected parser, object type, or invalid memory operation. Exploitation requires user interaction with attacker-controlled content, and successful code runs with the current user's privileges.

The record

CVE
CVE-2020-0979
Published
Apr 15, 2020
Updated
Aug 4, 2024
Vendor
Microsoft
Product
Microsoft 365 Apps for enterprise
Classifications
T1203, T1204.002
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?

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

  1. Affected versionversion=32-bit Systems
  2. Affected versionversion=64-bit Systems

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · Microsoft 365 Apps for enterpriseversion=32-bit Systems; version=64-bit Systems

Published CVSS scores

9.3NIST NVDAV:N/AC:M/Au:N/C:C/I:C/A:C
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/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.

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

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

T1203Exploitation for Client Execution
T1204.002User Execution: Malicious File

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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