FFmpeg before commit 9d786e4 contains a stack buffer overflow in the MPEG-PS muxer (libavformat/mpegenc.c). When muxing input with more streams than the muxers fixed-size stack buffer accommodates, the buffer is overflowed. A crafted input with an excessive number of streams triggers the overflow during MPEG-PS muxing.
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 |
|---|---|---|---|
| Ffmpeg | Ubuntu | devel | * |
| Ffmpeg | Ubuntu | esm-apps-legacy/xenial | * |
| Ffmpeg | Ubuntu | esm-apps/bionic | * |
| Ffmpeg | Ubuntu | esm-apps/focal | * |
| Ffmpeg | Ubuntu | esm-apps/jammy | * |
| Ffmpeg | Ubuntu | esm-apps/noble | * |
| Ffmpeg | Ubuntu | esm-apps/resolute | * |
| Ffmpeg | Ubuntu | jammy | * |
| Ffmpeg | Ubuntu | noble | * |
| Ffmpeg | Ubuntu | resolute | * |
| Ffmpeg | Ubuntu | upstream | * |
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].