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Fencer Intel
high 7.8

CVE-2021-31893 json

A vulnerability has been identified in SIMATIC PCS 7 V8.2 and earlier (All versions), SIMATIC PCS 7 V9.0 (All versions < V9.0 SP3), SIMATIC…

published 5y ago modified 4mo ago also EUVD-2021-18768

cvss
7.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 47%
public exploits
0
none known

Summary

A vulnerability has been identified in SIMATIC PCS 7 V8.2 and earlier (All versions), SIMATIC PCS 7 V9.0 (All versions < V9.0 SP3), SIMATIC PDM (All versions < V9.2), SIMATIC STEP 7 V5.X (All versions < V5.6 SP2 HF3), SINAMICS STARTER (containing STEP 7 OEM version) (All versions < V5.4 HF2). The affected software contains a buffer overflow vulnerability while handling certain files that could allow a local attacker to trigger a denial-of-service condition or potentially lead to remote code execution.

Patch / fix

  • siemens simatic_pdm_firmware 9.2
  • siemens sinamics_starter_firmware 5.4

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-21-194-05 updated cvss 7.8

Siemens SIMATIC Software Products

  • Siemens SIMATIC PCS 7 V8.2 and earlier
    affected: workaround, no fix available
  • Siemens SIMATIC PCS 7 V9.0 <V9.0_SP3
    affected: fixed in V9.0, workaround
  • Siemens SIMATIC PDM <V9.2
    affected: fixed in V9.2, workaround support.industry.siemens.com
  • Siemens SIMATIC STEP 7 V5.X <V5.6_SP2_HF3
    affected: fixed in V5.6, workaround support.industry.siemens.com
  • Siemens SINAMICS STARTER (containing STEP 7 OEM version) <V5.4_HF2
    affected: fixed in V5.4, workaround support.industry.siemens.com

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

Exploit prediction

0.56% chance of exploitation in the next 30 days, higher than 47% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.2 AV:L/AC:L/Au:N/C:C/I:C/A:C

Affected products

  • Siemens SIMATIC PCS 7 V8.2 and earlier
  • Siemens SIMATIC PCS 7 V9.0
  • Siemens SIMATIC PDM
  • Siemens SIMATIC STEP 7 V5.X
  • Siemens SINAMICS STARTER (containing STEP 7 OEM version)

Classification

Weakness
  • CWE-120 Buffer Copy without Checking Size of Input

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.