CVE-2020-28587Public exploit

Code execution via trusted Office Art record length

Published Feb 23, 2021 · Updated Aug 4, 2024

Heap-based buffer overflow in PlanMaker 2021 revision 1014 allows attackers to corrupt memory by inducing a victim to open a crafted Excel file. CEscherObject::ReadNativeProperties trusts the 32-bit length of a version/instance 0x001e record and copies more than 0x1d4 bytes into a fixed-size object member. Opening the file is required, and the resulting heap corruption can crash the application or enable code execution in its context.

CVSS severity8.8
High
EPSS probability0.95%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Heap-based buffer overflow in PlanMaker 2021 revision 1014 allows attackers to corrupt memory by inducing a victim to open a crafted Excel file. CEscherObject::ReadNativeProperties trusts the 32-bit length of a version/instance 0x001e record and copies more than 0x1d4 bytes into a fixed-size object member. Opening the file is required, and the resulting heap corruption can crash the application or enable code execution in its context.

The record

CVE
CVE-2020-28587
Published
Feb 23, 2021
Updated
Aug 4, 2024
Vendor
SoftMaker Software GmbH
Product
PlanMaker
Classifications
CWE-122, CWE-787, T1204.002, T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 23, 2021CVE 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

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=SoftMaker Software GmbH SoftMaker Office PlanMaker 2021 (Revision 1014)

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

SoftMaker Software GmbH · PlanMakerversion=SoftMaker Software GmbH SoftMaker Office PlanMaker 2021 (Revision 1014)

Published CVSS scores

6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P
8.8Cisco TalosCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
7.8NIST NVDCVSS:3.1/AV:L/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)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-122Heap-based Buffer Overflow
CWE-787Out-of-bounds Write
T1204.002Malicious File
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo