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Fencer Vulns
critical 9.8

CVE-2021-25668 json

A vulnerability has been identified in SCALANCE X200-4P IRT (All versions < 5.5.1), SCALANCE X201-3P IRT (All versions < 5.5.1), SCALANCE X…

published 2021-04-22 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-12560

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.6%
EPSS 1.6% chance of exploitation in 30 days, percentile 75%
public exploits
0
none known

Summary

A vulnerability has been identified in SCALANCE X200-4P IRT (All versions < 5.5.1), SCALANCE X201-3P IRT (All versions < 5.5.1), SCALANCE X201-3P IRT PRO (All versions < 5.5.1), SCALANCE X202-2 IRT (All versions < 5.5.1), SCALANCE X202-2P IRT (incl. SIPLUS NET variant) (All versions < 5.5.1), SCALANCE X202-2P IRT PRO (All versions < 5.5.1), SCALANCE X204 IRT (All versions < 5.5.1), SCALANCE X204 IRT PRO (All versions < 5.5.1), SCALANCE X204-2 (incl. SIPLUS NET variant) (All versions < V5.2.5), SCALANCE X204-2FM (All versions < V5.2.5), SCALANCE X204-2LD (incl. SIPLUS NET variant) (All versions < V5.2.5), SCALANCE X204-2LD TS (All versions < V5.2.5), SCALANCE X204-2TS (All versions < V5.2.5), SCALANCE X206-1 (All versions < V5.2.5), SCALANCE X206-1LD (All versions < V5.2.5), SCALANCE X208 (incl. SIPLUS NET variant) (All versions < V5.2.5), SCALANCE X208PRO (All versions < V5.2.5), SCALANCE X212-2 (incl. SIPLUS NET variant) (All versions < V5.2.5), SCALANCE X212-2LD (All versions < V5.2.5), SCALANCE X216 (All versions < V5.2.5), SCALANCE X224 (All versions < V5.2.5), SCALANCE XF201-3P IRT (All versions < 5.5.1), SCALANCE XF202-2P IRT (All versions < 5.5.1), SCALANCE XF204 (All versions < V5.2.5), SCALANCE XF204 IRT (All versions < 5.5.1), SCALANCE XF204-2 (incl. SIPLUS NET variant) (All versions < V5.2.5), SCALANCE XF204-2BA IRT (All versions < 5.5.1), SCALANCE XF206-1 (All versions < V5.2.5), SCALANCE XF208 (All versions < V5.2.5). Incorrect processing of POST requests in the webserver may result in write out of bounds in heap. An attacker might leverage this to cause denial-of-service on the device and potentially remotely execute code.

Patch / fix

  • siemens scalance_x200-4p_irt_firmware 5.5.1
  • siemens scalance_x201-3p_irt_firmware 5.5.1
  • siemens scalance_x201-3p_irt_pro_firmware 5.5.1
  • siemens scalance_x202-2_irt_firmware 5.5.1
  • siemens scalance_x202-2p_irt_pro_firmware 5.5.1
  • siemens scalance_x204_irt_firmware 5.5.1
  • siemens scalance_x204_irt_pro_firmware 5.5.1
  • siemens scalance_x204-2_firmware 5.2.5
  • siemens scalance_x204-2fm_firmware 5.2.5
  • siemens scalance_x204-2ld_firmware 5.2.5
  • siemens scalance_x204-2ld_ts_firmware 5.2.5
  • siemens scalance_x204-2ts_firmware 5.2.5
  • siemens scalance_x206-1_firmware 5.2.5
  • siemens scalance_x206-1ld_firmware 5.2.5
  • siemens scalance_x208_firmware 5.2.5
  • siemens scalance_x208pro_firmware 5.2.5
  • siemens scalance_x212-2_firmware 5.2.5
  • siemens scalance_x212-2ld_firmware 5.2.5
  • siemens scalance_x216_firmware 5.2.5
  • siemens scalance_x224_firmware 5.2.5

Vendor advisories

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

cisa ICSA-21-103-07 updated cvss 9.8

Siemens Web Server of SCALANCE X200 (Update A)

  • Siemens SCALANCE X200-4P IRT <5.5.1 Siemens SCALANCE X201-3P IRT <5.5.1 Siemens SCALANCE X201-3P IRT PRO <5.5.1 Siemens SCALANCE X202-2 IRT <5.5.1 Siemens SCALANCE X202-2P IRT (incl. SIPLUS NET variant) <5.5.1 Siemens SCALANCE X202-2P IRT PRO <5.5.1
    +2 more products
    Siemens SCALANCE X204 IRT <5.5.1 Siemens SCALANCE X204 IRT PRO <5.5.1
    affected: fixed in V5.5.1, mitigation support.industry.siemens.com
  • Siemens SCALANCE X204-2 (incl. SIPLUS NET variant) <V5.2.5 Siemens SCALANCE X204-2FM <V5.2.5 Siemens SCALANCE X204-2LD (incl. SIPLUS NET variant) <V5.2.5 Siemens SCALANCE X204-2LD TS <V5.2.5 Siemens SCALANCE X204-2TS <V5.2.5 Siemens SCALANCE X206-1 <V5.2.5
    +7 more products
    Siemens SCALANCE X206-1LD <V5.2.5 Siemens SCALANCE X208 (incl. SIPLUS NET variant) <V5.2.5 Siemens SCALANCE X208PRO <V5.2.5 Siemens SCALANCE X212-2 (incl. SIPLUS NET variant) <V5.2.5 Siemens SCALANCE X212-2LD <V5.2.5 Siemens SCALANCE X216 <V5.2.5 Siemens SCALANCE X224 <V5.2.5
    affected: fixed in V5.2.5, mitigation support.industry.siemens.com
  • Siemens SCALANCE XF201-3P IRT <5.5.1 Siemens SCALANCE XF202-2P IRT <5.5.1
    affected: fixed in V5.5.1, mitigation support.industry.siemens.com
  • Siemens SCALANCE XF204 <V5.2.5
    affected: fixed in V5.2.5, mitigation support.industry.siemens.com
  • Siemens SCALANCE XF204 IRT <5.5.1
    affected: fixed in V5.5.1, mitigation support.industry.siemens.com
  • Siemens SCALANCE XF204-2 (incl. SIPLUS NET variant) <V5.2.5
    affected: fixed in V5.2.5, mitigation support.industry.siemens.com
  • Siemens SCALANCE XF204-2BA IRT <5.5.1
    affected: fixed in V5.5.1, mitigation support.industry.siemens.com
  • Siemens SCALANCE XF206-1 <V5.2.5 Siemens SCALANCE XF208 <V5.2.5
    affected: fixed in V5.2.5, mitigation 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

1.57% chance of exploitation in the next 30 days, higher than 75% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

Affected products

  • Siemens SCALANCE X200-4P IRT
  • Siemens SCALANCE X201-3P IRT
  • Siemens SCALANCE X201-3P IRT PRO
  • Siemens SCALANCE X202-2 IRT
  • Siemens SCALANCE X202-2P IRT (incl. SIPLUS NET variant)
  • Siemens SCALANCE X202-2P IRT PRO
  • Siemens SCALANCE X204 IRT
  • Siemens SCALANCE X204 IRT PRO
  • Siemens SCALANCE X204-2 (incl. SIPLUS NET variant)
  • Siemens SCALANCE X204-2FM
  • Siemens SCALANCE X204-2LD (incl. SIPLUS NET variant)
  • Siemens SCALANCE X204-2LD TS
  • Siemens SCALANCE X204-2TS
  • Siemens SCALANCE X206-1
  • Siemens SCALANCE X206-1LD
  • Siemens SCALANCE X208 (incl. SIPLUS NET variant)
  • Siemens SCALANCE X208PRO
  • Siemens SCALANCE X212-2 (incl. SIPLUS NET variant)
  • Siemens SCALANCE X212-2LD
  • Siemens SCALANCE X216
  • Siemens SCALANCE X224
  • Siemens SCALANCE XF201-3P IRT
  • Siemens SCALANCE XF202-2P IRT
  • Siemens SCALANCE XF204
  • Siemens SCALANCE XF204 IRT
  • Siemens SCALANCE XF204-2 (incl. SIPLUS NET variant)
  • Siemens SCALANCE XF204-2BA IRT
  • Siemens SCALANCE XF206-1
  • Siemens SCALANCE XF208

Classification

Weakness

References

Sources

Fencer Vulns 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.