|
Safefile Library and Documentation
Careless attention to opening files, often caused by problems with path
traversal or shared directories, can expose applications to attacks on the file
names that they use. In this paper we present criteria to determine if a path
is safe from attack and how previous algorithms are not sufficient to protect
against such attacks. We then describe an algorithm to safely open a file when
in the presence of an attack (and how to detect the presence of such an
attack), and provide a new library of file open routines that embodies our
algorithm. These routines can be used as one-for-one substitutes for
conventional POSIX open and fopen calls.
- James A. Kupsch and Barton P. Miller,
"How to Open a File and Not Get Hacked (extended version)",
MIST Project Technical Report, March 2008.
[pdf].
- James A. Kupsch and Barton P. Miller,
"How to Open a File and Not Get Hacked",
2008 Third International Conference on Availability, Reliability
and Security (ARES), Barcelona, Spain, March 2008.
[pdf].
-
ARES 2008 presentation
[pdf].
-
Safefile library implements the ideas in the paper:
-
Safefile man pages.
|
