Certain NETGEAR devices are affected by a stack-based buffer overflow by an authenticated user. This affects CBR750 before 3.2.18.2, D6220 before 1.0.0.68, D6400 before 1.0.0.102, D8500 before 1.0.3.60, LAX20 before 1.1.6.28, MK62 before 1.0.6.116, MR60 before 1.0.6.116, MS60 before 1.0.6.116, R6300v2 before 1.0.4.50, R6400 before 1.0.1.68, R6400v2 before 1.0.4.118, R6700v3 before 1.0.4.118, R6900P before 1.3.3.140, R7000 before 1.0.11.116, R7000P before 1.3.3.140, R7850 before 1.0.5.68, R7900 before 1.0.4.38, R7900P before 1.4.2.84, R7960P before 1.4.2.84, R8000 before 1.0.4.68, R8000P before 1.4.2.84, RAX15 before 1.0.3.96, RAX20 before 1.0.3.96, RAX200 before 1.0.4.120, RAX35v2 before 1.0.3.96, RAX40v2 before 1.0.3.96, RAX43 before 1.0.3.96, RAX45 before 1.0.3.96, RAX50 before 1.0.3.96, RAX75 before 1.0.4.120, RAX80 before 1.0.4.120, RBK752 before 3.2.17.12, RBK852 before 3.2.17.12, RBR750 before 3.2.17.12, RBR850 before 3.2.17.12, RBS750 before 3.2.17.12, RBS850 before 3.2.17.12, RS400 before 1.5.1.80, and XR1000 before 1.0.0.58.
The product writes data past the end, or before the beginning, of the intended buffer.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Cbr750_firmware | Netgear | * | 3.2.18.2 (excluding) |
Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer.
Be wary that a language’s interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Examples include the Safe C String Library (SafeStr) by Messier and Viega [REF-57], and the Strsafe.h library from Microsoft [REF-56]. These libraries provide safer versions of overflow-prone string-handling functions.
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.
Consider adhering to the following rules when allocating and managing an application’s memory:
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].
Use a CPU and operating system that offers Data Execution Protection (using hardware NX or XD bits) or the equivalent techniques that simulate this feature in software, such as PaX [REF-60] [REF-61]. These techniques ensure that any instruction executed is exclusively at a memory address that is part of the code segment.
For more information on these techniques see D3-PSEP (Process Segment Execution Prevention) from D3FEND [REF-1336].