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Mozilla fixes Firefox zero-day actively exploited in attacks (www.bleepingcomputer.com)

submitted 3 weeks ago by [email protected] to c/[email protected]

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[–] [email protected] 6 points 3 weeks ago (1 children)

This type of flaw occurs when memory that has been freed is still used by the program

Am I understanding correctly that a memory leak has been fixed? Though it says that it relates specifically to "Animation timelines", so does it mean that the fix only affects the (small?) portion of the memory that's been used by that feature? Or any memory that should get freed but wasn't previously?

[–] PoolloverNathan 1 points 3 weeks ago

Based on your quite, this is a use-after-free, meaning that despite Firefox marking the memory region as free to be reallocated, it continues to use the memory. This is dangerous as an attacker may be able to allocate in that region, leetting them change the old structure's values.