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Vulnerability record · CVE-2021-25668 · published 22 April 2021

CVE-2021-25668: Siemens scalance x200-4p irt firmware heap-based buffer overflow vulnerability

Siemens · Scalance X200 4p Irt Firmware

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.

9.8 CVSS 3.1 Critical EPSS 1.6% · top 25.7% CWE-122 · Heap-based buffer overflowCWE-787 · Out-of-bounds write
9.8CVSS 3.1 base score, v2 7.5
1.6%EPSS exploitation probability, 30 days
NoNot in CISA KEV
29Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

Description

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.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

29 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://cert-portal.siemens.com/productcert/pdf/ssa-187092.pdf PatchVendor Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-187092.pdf PatchVendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2021-25669Siemens scalance x200-4p irt firmware stack-based buffer overflow vulnerabilityA 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…EPSS 2.1%9.8CVE-2021-29998Windriver vxworks out-of-bounds write vulnerabilityAn issue was discovered in Wind River VxWorks before 6.5. There is a possible heap overflow in dhcp client.EPSS 2.4%9.6CVE-2022-26649Siemens scalance x204-2 firmware classic buffer overflow vulnerabilityA vulnerability has been identified in SCALANCE X200-4P IRT (All versions < V5.5.2), SCALANCE X201-3P IRT (All versions < V5.5.2), SCALANCE X201-3P I…EPSS 1.3%8.8CVE-2022-26647Siemens scalance x200-4p irt firmware vulnerabilityA vulnerability has been identified in SCALANCE X200-4P IRT (All versions < V5.5.2), SCALANCE X201-3P IRT (All versions < V5.5.2), SCALANCE X201-3P I…EPSS 1.1%8.7CVE-2020-28400Siemens dk standard ethernet controller evaluation kit firmware allocation without limits vulnerabilityAffected devices contain a vulnerability that allows an unauthenticated attacker to trigger a denial of service condition. The vulnerability can be t…EPSS 1.9%8.2CVE-2022-26648Siemens scalance x204-2 firmware classic buffer overflow vulnerabilityA vulnerability has been identified in SCALANCE X200-4P IRT (All versions < V5.5.2), SCALANCE X201-3P IRT (All versions < V5.5.2), SCALANCE X201-3P I…EPSS 0.94%7.4CVE-2023-29054Siemens scalance x200-4p irt firmware inadequate encryption strength vulnerabilityA vulnerability has been identified in SCALANCE X200-4P IRT (All versions < V5.5.2), SCALANCE X201-3P IRT (All versions < V5.5.2), SCALANCE X201-3P I…EPSS 0.26%6.1CVE-2022-40631Siemens scalance x200-4p irt firmware cross-site scripting vulnerabilityA vulnerability has been identified in SCALANCE X200-4P IRT (All versions < V5.5.0), SCALANCE X201-3P IRT (All versions < V5.5.0), SCALANCE X201-3P I…EPSS 0.47%

Source: NIST National Vulnerability Database (record CVE-2021-25668), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.