Full Report
PSS(R)SINCAL uses WibuKey third-party product that contains an out-of-bounds write vulnerability. An attacker could exploit this vulnerability to cause a system crash, resulting in a denial-of-service condition. This affects PSS SINCAL only when configured to use the legacy WibuKey dongle license type. Siemens is actively preparing updates and recommends applicable mitigations for products where patches are currently unavailable.
Analysis Summary
# Vulnerability: WibuKey Out-of-Bounds Write in Siemens PSS®SINCAL
## CVE Details
- **CVE ID:** CVE-2026-84854
- **CVSS Score:** 7.0 (High)
- **CWE:** CWE-787: Out-of-bounds Write
## Affected Systems
- **Products:** Siemens PSS®SINCAL (Electric and pipe network simulation software)
- **Versions:**
- PSS®SINCAL V21.5: All versions
- PSS®SINCAL V22.0: All versions
- PSS®SINCAL V22.5: All versions prior to V22.5 Update 5
- **Configurations:** The vulnerability specifically affects systems configured to use the legacy **WibuKey dongle license type**.
## Vulnerability Description
The flaw exists within the third-party WibuKey driver used by PSS®SINCAL. The driver performs insufficient validation of user input when calculating the size of a kernel buffer. This allows small amounts of data to be written outside the intended buffer. In most cases, this leads to a system crash (Denial-of-Service); however, under specific circumstances, adjacent kernel memory can be modified.
## Exploitation
- **Status:** Not explicitly stated as exploited in the wild; no PoC linked in advisory.
- **Complexity:** High
- **Attack Vector:** Local (Requires local access to the system)
## Impact
- **Confidentiality:** High
- **Integrity:** High
- **Availability:** High (System crash resulting in DoS)
## Remediation
### Patches
- **PSS®SINCAL V22.5:** Update to **V22.5 Update 5** or later.
- **WibuKey Runtime:** For versions V21.5 and V22.0 (where no integrated PSS®SINCAL patch is currently available), manually install **WIBU Systems WibuKey Runtime for Windows 6.72** or later.
### Workarounds
- **Manual Driver Update:** If a PSS®SINCAL update is unavailable, manually download the WibuKey Runtime from the Wibu-Systems support page.
- **General Security:** Siemens recommends protecting network access via firewalls, segmentation, and VPNs to ensure the software runs in a protected IT environment.
- **Grid Resilience:** Operators of critical power systems should ensure multi-level redundant secondary protection schemes are in place to minimize the impact of a local system failure on the wider grid.
## Detection
- **Indicators of Compromise:** Unexpected system crashes (BSOD) or instability on workstations running PSS®SINCAL with legacy dongles.
- **Detection methods:** Audit installed software for WibuKey Runtime versions older than 6.72.
## References
- Siemens Security Advisory SSA-148322: hxxps[://]cert-portal[.]siemens[.]com/productcert/html/ssa-148322[.]html
- PSS®SINCAL Updates: hxxps[://]www[.]simtec[.]cc/en/updates[.]aspx
- Wibu-Systems User Software: hxxps[://]www[.]wibu[.]com/support/user/user-software[.]html
- Siemens ProductCERT: hxxps[://]www[.]siemens[.]com/cert/advisories