KEPServerEX: v6.0 to v6.9, ThingWorx Kepware Server: v6.8 and v6.9, ThingWorx Industrial Connectivity: All versions, OPC-Aggregator: All versions, Rockwell Automation KEPServer Enterprise, GE Digital Industrial Gateway Server: v7.68.804 and v7.66, Software Toolbox TOP Server: All 6.x versions are vulnerable to a stack-based buffer overflow. Opening a specifically crafted OPC UA message could allow an attacker to crash the server and remotely execute code.
Weakness
A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Industrial_gateway_server | Ge | 7.66 (including) | 7.66 (including) |
| Industrial_gateway_server | Ge | 7.68.804 (including) | 7.68.804 (including) |
| Kepware_kepserverex | Ptc | 6.0 (including) | 6.0 (including) |
| Kepware_kepserverex | Ptc | 6.9 (including) | 6.9 (including) |
| Opc-aggregator | Ptc | - (including) | - (including) |
| Thingworx_industrial_connectivity | Ptc | - (including) | - (including) |
| Thingworx_kepware_server | Ptc | 6.8 (including) | 6.8 (including) |
| Thingworx_kepware_server | Ptc | 6.9 (including) | 6.9 (including) |
| Kepserver_enterprise | Rockwellautomation | 6.6.504.0 (including) | 6.6.504.0 (including) |
| Kepserver_enterprise | Rockwellautomation | 6.9.572.0 (including) | 6.9.572.0 (including) |
| Top_server | Softwaretoolbox | 6.0 (including) | 6.9 (including) |
Potential Mitigations
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking.
- D3-SFCV (Stack Frame Canary Validation) from D3FEND [REF-1334] discusses canary-based detection in detail.
- Run or compile the software using features or extensions that randomly arrange the positions of a program’s executable and libraries in memory. Because this makes the addresses unpredictable, it can prevent an attacker from reliably jumping to exploitable code.
- Examples include Address Space Layout Randomization (ASLR) [REF-58] [REF-60] and Position-Independent Executables (PIE) [REF-64]. Imported modules may be similarly realigned if their default memory addresses conflict with other modules, in a process known as “rebasing” (for Windows) and “prelinking” (for Linux) [REF-1332] using randomly generated addresses. ASLR for libraries cannot be used in conjunction with prelink since it would require relocating the libraries at run-time, defeating the whole purpose of prelinking.
- For more information on these techniques see D3-SAOR (Segment Address Offset Randomization) from D3FEND [REF-1335].