CVE-2021-27399

Code execution via modfem parser out-of-bounds write

Published Jun 8, 2021 · Updated Aug 3, 2024

Out-of-bounds write in Siemens Simcenter Femap 2020.2 and 2021.1 allows remote attackers to execute code through a crafted modfem file. The femap.exe modfem parser fails to validate user-controlled data and writes before the start of an allocated structure. Exploitation requires a user to open the malicious file or visit a page that supplies it, and code runs with the current process privileges.

CVSS severity7.8
High
EPSS probability1.34%
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 Siemens Simcenter Femap 2020.2 and 2021.1 allows remote attackers to execute code through a crafted modfem file. The femap.exe modfem parser fails to validate user-controlled data and writes before the start of an allocated structure. Exploitation requires a user to open the malicious file or visit a page that supplies it, and code runs with the current process privileges.

The record

CVE
CVE-2021-27399
Published
Jun 8, 2021
Updated
Aug 3, 2024
Vendor
Siemens
Product
Simcenter Femap
Classifications
CWE-787, T1204.002, T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 8, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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=All versions < V2020.2.MP3
  2. Affected versionversion=All versions < V2021.1.MP3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Siemens · Simcenter Femapversion=All versions < V2020.2.MP3; version=All versions < V2021.1.MP3

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P

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 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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