Security Blog
The latest news and insights from Google on security and safety on the Internet
FFmpeg and a thousand fixes
10 janvier 2014
Posted by Mateusz Jurczyk and Gynvael Coldwind, Information Security Engineers
At Google, security is a top priority - not only for our own products, but across the entire Internet. That’s why members of the Google Security Team and other Googlers frequently perform audits of software and report the resulting findings to the respective vendors or maintainers, as shown in the official “
Vulnerabilities - Application Security
” list. We also try to employ the extensive computing power of our data centers in order to solve some of the security challenges by performing large-scale automated testing, commonly known as fuzzing.
One internal fuzzing effort we have been running continuously for the past two years is the testing process of
FFmpeg
, a large cross-platform solution to record, convert and stream audio and video written in C. It is used in multiple applications and software libraries such as Google Chrome, MPlayer, VLC or xine. We started relatively small by making use of trivial mutation algorithms, some 500 cores and input media samples gathered from readily available sources such as the
samples.mplayerhq.hu
sample base and FFmpeg FATE regression testing suite. Later on, we grew to more complex and effective mutation methods, 2000 cores and an input corpus supported by sample files improving the overall code coverage.
Following more than two years of work, we are happy to announce that the FFmpeg project has incorporated more than a thousand fixes to bugs (including some security issues) that we have discovered in the project so far:
$ git log | grep Jurczyk | grep -c Coldwind
1120
This event clearly marks an important milestone in our ongoing fuzzing effort.
FFmpeg robustness and security has clearly improved over time. When we started the fuzzing process and had initial results, we contacted the project maintainer - Michael Niedermayer - who submitted the first fix on the 24th of January, 2012 (see commit
c77be3a35a0160d6af88056b0899f120f2eef38e
). Since then, we have carried out several dozen fuzzing iterations (each typically resulting in less crashes than the previous ones) over the last two years, identifying bugs of a number of different classes:
NULL pointer dereferences,
Invalid pointer arithmetic leading to SIGSEGV due to unmapped memory access,
Out-of-bounds reads and writes to stack, heap and static-based arrays,
Invalid free() calls,
Double free() calls over the same pointer,
Division errors,
Assertion failures,
Use of uninitialized memory.
We have simultaneously worked with the developers of Libav, an independent fork of FFmpeg, in order to have both projects represent an equal, high level of robustness and security posture. Today, Libav is at 413 fixes and the library is slowly but surely catching up with FFmpeg.
We are continuously improving our corpus and fuzzing methods and will continue to work with both FFmpeg and Libav to ensure the highest quality of the software as used by millions of users behind multiple media players. Until we can declare both projects "fuzz clean" we recommend that people refrain from using either of the two projects to process untrusted media files. You can also use privilege separation on your PC or production environment when absolutely required.
Of course, we would not be able to do this without the hard work of all the developers involved in the fixing process. If you are interested in the effort, please keep an eye on the master branches for commits marked as
"Found by Mateusz "j00ru" Jurczyk and Gynvael Coldwind"
and watch out for new stable versions of the software packages.
For more details, see the “FFmpeg and a thousand fixes” posts at the authors’ personal blogs
here
or
here
.
Libellés
#sharethemicincyber
#supplychain #security #opensource
android
android security
android tr
app security
big data
biometrics
blackhat
C++
chrome
chrome enterprise
chrome security
connected devices
CTF
diversity
encryption
federated learning
fuzzing
Gboard
google play
google play protect
hacking
interoperability
iot security
kubernetes
linux kernel
memory safety
Open Source
pha family highlights
pixel
privacy
private compute core
Rowhammer
rust
Security
security rewards program
sigstore
spyware
supply chain
targeted spyware
tensor
Titan M2
VDP
vulnerabilities
workshop
Archive
2024
nov.
oct.
sept.
août
juil.
juin
mai
avr.
mars
févr.
janv.
2023
déc.
nov.
oct.
sept.
août
juil.
juin
mai
avr.
mars
févr.
janv.
2022
déc.
nov.
oct.
sept.
août
juil.
juin
mai
avr.
mars
févr.
janv.
2021
déc.
nov.
oct.
sept.
août
juil.
juin
mai
avr.
mars
févr.
janv.
2020
déc.
nov.
oct.
sept.
août
juil.
juin
mai
avr.
mars
févr.
janv.
2019
déc.
nov.
oct.
sept.
août
juil.
juin
mai
avr.
mars
févr.
janv.
2018
déc.
nov.
oct.
sept.
août
juil.
juin
mai
avr.
mars
févr.
janv.
2017
déc.
nov.
oct.
sept.
juil.
juin
mai
avr.
mars
févr.
janv.
2016
déc.
nov.
oct.
sept.
août
juil.
juin
mai
avr.
mars
févr.
janv.
2015
déc.
nov.
oct.
sept.
août
juil.
juin
mai
avr.
mars
févr.
janv.
2014
déc.
nov.
oct.
sept.
août
juil.
juin
avr.
mars
févr.
janv.
2013
déc.
nov.
oct.
août
juin
mai
avr.
mars
févr.
janv.
2012
déc.
sept.
août
juin
mai
avr.
mars
févr.
janv.
2011
déc.
nov.
oct.
sept.
août
juil.
juin
mai
avr.
mars
févr.
2010
nov.
oct.
sept.
août
juil.
mai
avr.
mars
2009
nov.
oct.
août
juil.
juin
mars
2008
déc.
nov.
oct.
août
juil.
mai
févr.
2007
nov.
oct.
sept.
juil.
juin
mai
Feed
Follow @google
Follow
Give us feedback in our
Product Forums
.