from the so-you-thought-you-were-safe? dept.
Submitted via IRC for Bytram
If your desktop runs a mainstream release of Linux, chances are you're vulnerable.
[...] While Evans' attacks won't work on most Linux servers, they will reliably compromise most desktop versions of Linux, which employees at Google, Facebook, and other security conscious companies often use in an attempt to avoid the pitfalls of Windows and Mac OS X. Three weeks ago, Evans released a separate Linux zero-day that had similarly dire consequences.
"I like to prove that vulnerabilities are not just theoretical—that they are actually exploitable to cause real problems," Evans told Ars when explaining why he developed—and released—an exploit for fully patched systems. "Unfortunately, there's still the occasional vulnerability disclosure that is met with skepticism about exploitability. I'm helping to stamp that out."
Like Evans' previous Linux zero-day, the proof-of-concept attacks released Tuesday exploit a memory-corruption vulnerability closely tied to GStreamer, a media framework that by default ships with many mainstream Linux distributions. This time, the exploit takes aim at a flaw in a software library alternately known as Game Music Emu and libgme, which is used to emulate music from game consoles. The two audio files are encoded in the SPC music format used in the Super Nintendo Entertainment System console from the 1990s. Both take aim at a heap overflow bug contained in code that emulates the console's Sony SPC700 processor. By changing the .spc extension to .flac and .mp3, GSteamer and Game Music Emu automatically open them.
The exploit ending in .flac works as a drive-by attack when a Fedora 25 user visits a booby-trapped webpage. With nothing more than a click required, the file will open the desktop calculator. With modification, it could load any code an attacker chooses and execute it with the same system privileges afforded to the user. While users typically don't have the same unfettered system privileges granted to root, the ones they do have are plenty powerful. Such an exploit can, for instance, read and steal all the user's most personal data, including documents, pictures, e-mail, and chat transcripts. It could also steal the user's browser cookies and sessions for Gmail, Facebook, Twitter, and other sites. It could additionally persist across reboots, although not as stealthily as a root exploit. And as is growing increasingly common, it could be combined with a local root privilege exploit to gain full system rights.
[...] a few days ago Red Hat Legal provided the permission to ship MP3 encoding in Fedora. [...] it will soon be possible to convert physical media or other formats to MP3 in Fedora without 3rd party repositories.