Mozilla Foundation Security Advisory 2009-59

Heap buffer overflow in string to number conversion

Announced
October 27, 2009
Reporter
Alin Rad Pop
Impact
Critical
Products
Firefox
Fixed in
  • Firefox 3.0.15
  • Firefox 3.5.4

Description

Security researcher Alin Rad Pop of Secunia Research reported a heap-based buffer overflow in Mozilla's string to floating point number conversion routines. Using this vulnerability an attacker could craft some malicious JavaScript code containing a very long string to be converted to a floating point number which would result in improper memory allocation and the execution of an arbitrary memory location. This vulnerability could thus be leveraged by the attacker to run arbitrary code on a victim's computer.

Update: The underlying flaw in the dtoa routines used by Mozilla appears to be essentially the same as that reported against the libc gdtoa routine by Maksymilian Arciemowicz.

Workaround

Disable JavaScript until a version containing these fixes can be installed.

References