Memory safety bugs were reported in Firefox 59, Firefox ESR 52.7, and Thunderbird 52.7. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Thunderbird < 52.8, Thunderbird ESR < 52.8, Firefox < 60, and Firefox ESR < 52.8.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.