Vulnerability Database

383,371

Total vulnerabilities in the database

CVE-2021-40358 — siemens / simatic_pcs_7

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

A vulnerability has been identified in SIMATIC PCS 7 V8.2 (All versions), SIMATIC PCS 7 V9.0 (All versions < V9.0 SP3 UC04), SIMATIC PCS 7 V9.1 (All versions < V9.1 SP1), SIMATIC WinCC V15 and earlier (All versions < V15 SP1 Update 7), SIMATIC WinCC V16 (All versions < V16 Update 5), SIMATIC WinCC V17 (All versions < V17 Update 2), SIMATIC WinCC V7.4 (All versions < V7.4 SP1 Update 19), SIMATIC WinCC V7.5 (All versions < V7.5 SP2 Update 5). Legitimate file operations on the web server of the affected systems do not properly neutralize special elements within the pathname. An attacker could then cause the pathname to resolve to a location outside of the restricted directory on the server and read, write or delete unexpected critical files.

  • Published: Nov 9, 2021
  • Updated: Sep 13, 2026
  • CVE: CVE-2021-40358
  • Severity: Critical
  • Exploit:
  • CISA KEV:

CVSS v3:

  • Severity: Critical
  • Score: 9.9
  • AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

CVSS v2:

  • Severity: High
  • Score: 7.5
  • AV:N/AC:L/Au:N/C:P/I:P/A:P
Software Affected versions
siemens / simatic_pcs_7 = 8.2
siemens / simatic_pcs_7 = 9.0
siemens / simatic_pcs_7 = 9.1
siemens / simatic_wincc = 7.4
siemens / simatic_wincc = 7.4-sp1
siemens / simatic_wincc = 7.4-sp1_update1
siemens / simatic_wincc = 7.4-sp1_update10
siemens / simatic_wincc = 7.4-sp1_update11
siemens / simatic_wincc = 7.4-sp1_update12
siemens / simatic_wincc = 7.4-sp1_update13
siemens / simatic_wincc = 7.4-sp1_update14
siemens / simatic_wincc = 7.4-sp1_update15
siemens / simatic_wincc = 7.4-sp1_update16
siemens / simatic_wincc = 7.4-sp1_update17
siemens / simatic_wincc = 7.4-sp1_update18
siemens / simatic_wincc = 7.4-sp1_update2
siemens / simatic_wincc = 7.4-sp1_update3
siemens / simatic_wincc = 7.4-sp1_update4
siemens / simatic_wincc = 7.4-sp1_update5
siemens / simatic_wincc = 7.4-sp1_update6
siemens / simatic_wincc = 7.4-sp1_update7
siemens / simatic_wincc = 7.4-sp1_update8
siemens / simatic_wincc = 7.4-sp1_update9
siemens / simatic_wincc = 7.4-update_1
siemens / simatic_wincc = 7.5
siemens / simatic_wincc = 7.5-sp1
siemens / simatic_wincc = 7.5-sp1_update1
siemens / simatic_wincc = 7.5-sp1_update2
siemens / simatic_wincc = 7.5-sp2
siemens / simatic_wincc = 7.5-sp2_update1
siemens / simatic_wincc = 7.5-sp2_update2
siemens / simatic_wincc = 7.5-sp2_update3
siemens / simatic_wincc = 7.5-sp2_update4
siemens / simatic_wincc = 15
siemens / simatic_wincc = 15.1
siemens / simatic_wincc = 15.1-update_1
siemens / simatic_wincc = 15.1-update_2
siemens / simatic_wincc = 15.1-update_3
siemens / simatic_wincc = 15.1-update_4
siemens / simatic_wincc = 15.1-update_5
siemens / simatic_wincc = 15.1-update_6
siemens / simatic_wincc = 16-update1
siemens / simatic_wincc = 16-update2
siemens / simatic_wincc = 16-update3
siemens / simatic_wincc = 16-update4
siemens / simatic_wincc = 17
siemens / simatic_wincc = 17-update1

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.