CVE-2021-25669

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-04-22 · updated 2026-06-17
Weakness: CWE-121

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 web server may write out of bounds in stack. An attacker might leverage this to denial-of-service of the device or remote code execution.

Affected products

Siemens Scalance X200-4P Irt Firmware: before 5.5.1 — fixed in 5.5.1
Siemens Scalance X201-3P Irt Firmware: before 5.5.1 — fixed in 5.5.1
Siemens Scalance X201-3P Irt Pro Firmware: before 5.5.1 — fixed in 5.5.1
Siemens Scalance X202-2 Irt Firmware: before 5.5.1 — fixed in 5.5.1
Siemens Scalance X202-2P Irt Firmware: before 5.5.1 — fixed in 5.5.1
Siemens Scalance X202-2P Irt Pro Firmware: before 5.5.1 — fixed in 5.5.1
Siemens Scalance X204-2 Firmware: before 5.2.5 — fixed in 5.2.5
Siemens Scalance X204-2Fm Firmware: before 5.2.5 — fixed in 5.2.5
Siemens Scalance X204-2Ld Firmware: before 5.2.5 — fixed in 5.2.5
Siemens Scalance X204-2Ld Ts Firmware: before 5.2.5 — fixed in 5.2.5
Siemens Scalance X204-2Ts Firmware: before 5.2.5 — fixed in 5.2.5
Siemens Scalance X204 Irt Firmware: before 5.5.1 — fixed in 5.5.1
Siemens Scalance X204 Irt Pro Firmware: before 5.5.1 — fixed in 5.5.1
Siemens Scalance X206-1 Firmware: before 5.2.5 — fixed in 5.2.5
Siemens Scalance X206-1Ld Firmware: before 5.2.5 — fixed in 5.2.5
Siemens Scalance X208 Firmware: before 5.2.5 — fixed in 5.2.5
Siemens Scalance X208Pro Firmware: before 5.2.5 — fixed in 5.2.5
Siemens Scalance X212-2 Firmware: before 5.2.5 — fixed in 5.2.5
Siemens Scalance X212-2Ld Firmware: before 5.2.5 — fixed in 5.2.5
Siemens Scalance X216 Firmware: before 5.2.5 — fixed in 5.2.5
Siemens Scalance X224 Firmware: before 5.2.5 — fixed in 5.2.5
Siemens Scalance Xf201-3P Irt Firmware: before 5.5.1 — fixed in 5.5.1
Siemens Scalance Xf202-2P Irt Firmware: before 5.5.1 — fixed in 5.5.1
Siemens Scalance Xf204-2 Firmware: before 5.2.5 — fixed in 5.2.5
Siemens Scalance Xf204-2Ba Irt Firmware: before 5.5.1 — fixed in 5.5.1
Siemens Scalance Xf204 Firmware: before 5.2.5 — fixed in 5.2.5
Siemens Scalance Xf204 Irt Firmware: before 5.5.1 — fixed in 5.5.1
Siemens Scalance Xf206-1 Firmware: before 5.2.5 — fixed in 5.2.5
Siemens Scalance Xf208 Firmware: before 5.2.5 — fixed in 5.2.5

How to fix

Upgrade to a fixed version: 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 Firmware 5.5.1; Siemens Scalance X202-2P 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 X204 Irt Firmware 5.5.1. Check the vendor advisory for mitigations.

References

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