Full Report
Multiple vulnerabilities affect various third-party components of the RUGGEDCOM Operating System (ROS). If exploited, an attacker could cause a denial-of-service, act as a man-in-the-middle or retrieval of sensitive information or gain privileged functions. Siemens has released new versions for several affected products and recommends to update to the latest versions. Siemens recommends specific countermeasures for products where fixes are not, or not yet available.
Analysis Summary
# Vulnerability: Third-Party Component Vulnerabilities in RUGGEDCOM Operating System (ROS)
## CVE Details
- **CVE ID:** CVE-2021-37208, CVE-2021-42016, CVE-2021-42017, CVE-2021-42018, CVE-2021-42019, CVE-2021-42020
- **CVSS Score:** 9.6 (Critical) - *Highest aggregate base score*
- **CWE:**
- CWE-121: Stack-based Buffer Overflow
- CWE-122: Heap-based Buffer Overflow
- CWE-190: Integer Overflow or Wraparound
- CWE-754: Improper Check for Unusual or Exceptional Conditions
## Affected Systems
- **Products:**
- RUGGEDCOM M969F, M2100F, M2200F
- RUGGEDCOM i800 / i800NC
- RUGGEDCOM RS416v2 / RS416Pv2 (including NC variants)
- RUGGEDCOM RSG2100P / RSG2100PNC (32M)
- RUGGEDCOM ROS V4.X and V5.X families
- **Versions:**
- i800/i800NC: All versions < V4.3.8
- Various other ROS V4.X and V5.X products (refer to advisory for specific lifecycle status).
- **Configurations:** Devices with TFTP functionality enabled are specifically susceptible to certain CVEs; on FIPS devices, enabling TFTP reverts the device to regular ROS mode.
## Vulnerability Description
Multiple vulnerabilities exist in third-party components integrated into ROS:
- **Memory Corruption (CVE-2021-37208, CVE-2021-42016, CVE-2021-42017):** Stack and heap-based buffer overflows in various components allow for remote code execution or Denial of Service (DoS).
- **Integer Overflow (CVE-2021-42019):** A failure to check memory boundaries during partition size allocation allows an attacker to cause an integer wrap-around, leading to undersized memory allocation and potential exploitation.
- **TFTP Flaws (CVE-2021-42020):** Improper null-termination handling in TFTP filenames can lead to data corruption or application "hard-faults."
## Exploitation
- **Status:** PoC available (indicated by CVSS "E:P" exploit code).
- **Complexity:** Low to High (varies by CVE; CVE-2021-42019 is High, others are Low).
- **Attack Vector:** Network.
## Impact
- **Confidentiality:** High
- **Integrity:** High
- **Availability:** High
- **Overall Result:** Attackers may gain privileged functions, cause DoS, or act as a Man-in-the-Middle (MitM).
## Remediation
### Patches
- **RUGGEDCOM i800/i800NC:** Update to V4.3.8 or later.
- **Other V4.X/V5.X Products:** Refer to the Siemens support portal for specific version updates (V4.3.8 or V5.x lineages).
- **Note:** For certain legacy hardware (M969F, M2100F, M2200F), no fix is currently planned.
### Workarounds
- Disable the TFTP service if not required.
- Segment the network to ensure the management interface is only accessible from a trusted network.
- Apply "Defense-in-Depth" by restricting access to the device to authorized personnel and systems only.
## Detection
- **Indicators of Compromise:** Unexpected device reboots (hard-faults), unauthorized configuration changes, or unusual TFTP traffic.
- **Detection methods:** Monitor network traffic for malformed TFTP packets and audit ROS system logs for memory-related error messages.
## References
- Siemens Advisory SSA-256353: hxxps://cert-portal[.]siemens[.]com/productcert/pdf/ssa-256353[.]pdf
- Siemens ProductCERT: hxxps://www[.]siemens[.]com/cert/advisories
- Asset Update Link: hxxps://support[.]industry[.]siemens[.]com/cs/ww/en/view/109816735/