Stack-based buffer overflow in the getSWFlag function in Foscam Cameras C1 Lite V3, and C1 V3 with firmware 2.82.2.33 and earlier, FI9800P V3, FI9803P V4, FI9851P V3, and FI9853EP V2 2.84.2.33 and earlier, FI9816P V3, FI9821EP V2, FI9821P V3, FI9826P V3, and FI9831P V3 2.81.2.33 and earlier, C1, C1 V2, C1 Lite, and C1 Lite V2 2.52.2.47 and earlier, FI9800P, FI9800P V2, FI9803P V2, FI9803P V3, and FI9851P V2 2.54.2.47 and earlier, FI9815P, FI9815P V2, FI9816P, and FI9816P V2, 2.51.2.47 and earlier, R2 and R4 2.71.1.59 and earlier, C2 and FI9961EP 2.72.1.59 and earlier, FI9900EP, FI9900P, and FI9901EP 2.74.1.59 and earlier, FI9928P 2.74.1.58 and earlier, FI9803EP and FI9853EP 2.22.2.31 and earlier, FI9803P and FI9851P 2.24.2.31 and earlier, FI9821P V2, FI9826P V2, FI9831P V2, and FI9821EP 2.21.2.31 and earlier, FI9821W V2, FI9831W, FI9826W, FI9821P, FI9831P, and FI9826P 2.11.1.120 and earlier, FI9818W V2 2.13.2.120 and earlier, FI9805W, FI9804W, FI9804P, FI9805E, and FI9805P 2.14.1.120 and earlier, FI9828P, and FI9828W 2.13.1.120 and earlier, and FI9828P V2 2.11.1.133 and earlier allows remote attackers to cause a denial of service (crash and reboot), via the callbackJson parameter.
The product writes data past the end, or before the beginning, of the intended buffer.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| C1_lite_firmware | Foscam | * | 2.82.2.33 (including) |
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].