Full Report
Multiple out-of-bounds vulnerabilities in third-party components are affecting SITOP UPS1600 before V2.5.4. Attackers could exploit these vulnerabilities and cause limited impact in the affected systems. Siemens has released new versions for the affected products and recommends to update to the latest versions.
Analysis Summary
# Vulnerability: Out-of-Bounds Write Vulnerabilities in SITOP UPS1600 Due to Third-Party NTP Component
## CVE Details
- CVE ID: CVE-2023-26552, CVE-2023-26553, CVE-2023-26554 (Multiple)
- CVSS Score: 5.6 (Medium)
- CWE: CWE-787: Out-of-bounds Write (Associated with all listed CVEs)
## Affected Systems
- Products: SITOP UPS1600 (10 A Ethernet/ PROFINET (6EP4134-3AB00-2AY0), 20 A Ethernet/ PROFINET (6EP4136-3AB00-2AY0), 40 A Ethernet/ PROFINET (6EP4137-3AB00-2AY0), EX 20 A Ethernet PROFINET (6EP4136-3AC00-2AY0))
- Versions: All versions prior to V2.5.4
- Configurations: Affects systems utilizing the vulnerable third-party NTP component versions.
## Vulnerability Description
Multiple Out-of-Bounds Write vulnerabilities exist in the `mstolfp.c` file within the affected third-party NTP component (specifically NTP 4.2.8p15). These flaws stem from improper handling during string-to-float conversion operations:
1. **CVE-2023-26552:** Out-of-bounds write when adding a decimal point.
2. **CVE-2023-26553:** Out-of-bounds write when copying the trailing number.
3. **CVE-2023-26554:** Out-of-bounds write when adding a null ('\0') character.
If exploited, these weaknesses could lead to memory corruption within the targeted process.
## Exploitation
- Status: Not explicitly stated as exploited in the wild, but Proof-of-Concept (PoC) potential exists due to the nature derived from NTP flaws.
- Complexity: High (Attackers may be able to attack a client `ntpq` process, but explicitly *cannot* attack `ntpd`). This implies target interaction or specific conditions are required.
- Attack Vector: Network (Implied by targeting `ntpq` client process remotely).
## Impact
- Confidentiality: Low
- Integrity: Low
- Availability: Low
*(Note: The advisory states the impact is "limited" for all systems.)*
## Remediation
### Patches
- Update SITOP UPS1600 to version **V2.5.4 or later**. Specific download link provided by Siemens: `https://support.industry.siemens.com/cs/ww/en/view/79207181/`
### Workarounds
- Follow Siemens General Security Recommendations, which strongly advise protecting network access to devices using appropriate mechanisms.
- Configure the environment according to Siemens' operational guidelines for Industrial Security.
## Detection
- Detection methods specific to these CVEs were not detailed in the advisory summary.
- **General Indicator:** Monitor network traffic targeting vulnerable devices for anomalous activity that might attempt to interact with NTP client processes (`ntpq`).
## References
- Vendor Advisory: Siemens Security Advisory SSA-238730
- Siemens Industrial Security: `https://www.siemens.com/industrialsecurity`
- Siemens Operational Guidelines: `https://www.siemens.com/cert/operational-guidelines-industrial-security`