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Firefox 4: OpenType font feature support

hacks.mozilla.org

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Re: Firefox 4: OpenType font feature support

#4
Several years ago, the WebKit folks added support for web fonts (TrueType fonts, in particular). It seemed harmless enough.

They didn't talk to the core OS X people, who assumed that fonts would largely be trusted entities. The file format for TTF is quite complex, in reality, and allows for a wide variety of attack. At that time, there were dozens of easily exploitable vulnerabilities in how OS X handled TTF fonts.

Most of these have been fixed by now, however. I would assume the Mozilla foundation would have the foresight to avoid a repeat of such situations, and all rendering code would have been fully fuzzed.

Re: Firefox 4: OpenType font feature support

#5

Several years ago, the WebKit folks added support for web fonts (TrueType fonts, in particular). It seemed harmless enough. They didn't talk to the core OS X people, who assumed that fonts would largely be trusted entities. The file format for TTF is quite complex, in reality, and allows for a wide variety of attack. At that time, there were dozens of easily exploitable vulnerabilities in how OS X handled TTF fonts.…

Yes, Mozilla's security does have a font fuzzer (along with the JavaScript fuzzer and DOM fuzzer that have been instrumental in finding security holes before the bad guys do):

http://www.squarefree.com/2010/07/14/fuzzing-talk-at-the-moz...

https://wiki.mozilla.org/Firefox3.1/Downloadable_Fonts_Secur...