Why not?!?
File permissions allow everybody write access to the file.
The path via /proc to the file has been created when the initial path
via /tmp was wide open.
Closing the initial path via /tmp has no effect on the /proc path
And due to the actual file permissions the read-only fd can easily
changed to read-write.
Marco
Sent from my iPhone 3G(s)
On 26 okt 2009, at 22:58, p...@maths.usyd.edu.au wrote:
Dear Casper and Dan,
If you can control<pid>, then clearly you have access the file anyway
simply by controlling it using a debugger.
Sorry, but no. The "attacker" has the file opened O_RDONLY, and cannot
"upgrade" that to O_RDWR.
Cheers, Paul
Paul Szabo p...@maths.usyd.edu.au http://www.maths.usyd.edu.au/u/psz/
School of Mathematics and Statistics University of Sydney
Australia
