memory corruption in variable assignments

marcIhm / yabasic

Yabasic - A simple Basic interpreter for Unix and Windows

http://www.yabasic.de

MIT License

90 stars 17 forks source link

memory corruption in variable assignments #5

Closed ginggs closed 7 years ago

ginggs commented 7 years ago

From https://bugs.launchpad.net/ubuntu/+source/yabasic/+bug/424602

A user can corrupt memory, possibly executing code during yabasic's parsing of BASIC files. Using a large value when assigning variables will overflow a buffer and corrupt memory (looks like it could be a pointer on the stack).

The bug report includes an attachment, 191.bas, containing the following: fuzz = AAAAA... The letter 'A' was repeated 550 times.

marcIhm commented 7 years ago

Hi Graham, thanx for forwarding this; important (and easy) to correct ... regards Marc