CVE-2021-42028

Code execution via out-of-bounds BMP write

Published Jan 4, 2024 · Updated Jun 17, 2025

Out-of-bounds write in Siemens syngo fastView affects all versions and allows attackers to execute code when a user opens a crafted BMP file. The BMP parser fails to validate user-supplied image data and writes past the end of an allocated structure. Exploitation requires user interaction and runs code with the current process's privileges; the malformed input can also crash the viewer.

CVSS severity7.8
High
EPSS probability0.32%
Next 30 days · Sep 17, 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

Out-of-bounds write in Siemens syngo fastView affects all versions and allows attackers to execute code when a user opens a crafted BMP file. The BMP parser fails to validate user-supplied image data and writes past the end of an allocated structure. Exploitation requires user interaction and runs code with the current process's privileges; the malformed input can also crash the viewer.

The record

CVE
CVE-2021-42028
Published
Jan 4, 2024
Updated
Jun 17, 2025
Vendor
Siemens
Product
syngo fastView
Classifications
CWE-787, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 4, 2024CVE publishedPublication date reported by the CVE source.
  2. Jun 17, 2025Record 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=All versions

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Siemens · syngo fastViewversion=All versions

Published CVSS scores

7.8Siemens AGCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
7.8NVDCVSS: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 11, 2026Sep 17, 2026
Latest reporting daySep 17, 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
T1204.002Malicious 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

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