Application: Cytel Studio: StatXact / LogXact / CrossOver http://www.cytel.com/Software/StatXact.aspx http://www.cytel.com/Software/LogXact.aspx http://www.cytel.com/Software/Crossover.aspx Versions: <= 9.0.0 Platforms: Windows Bugs: A] strings stack overflow B] rows integer overflow C] CYB USE stack overflow Exploitation: file Date: 02 Oct 2011 Author: Luigi Auriemma e-mail: firstname.lastname@example.org web: aluigi.org
1) Introduction 2) Bugs 3) The Code 4) Fix
=============== 1) Introduction ===============
From vendor's website: "Cytel, the acknowledged leader in exact statistical methods, helped pioneer exact methods for binary logistic regression and multinomial regression." "First introduced in 1987, LogXact is unequivocally the fastest and most powerful logistic regression analysis software available today." "With StatXact, Cytel's own powerful algorithms make exact inferences by permuting the actually observed data, eliminating the need for distributional assumptions."
======= 2) Bugs =======
Buffer overflow during the copying of the strings in a stack buffer of 256 bytes.
There is an integer overflow in the handling of the rows. The number of rows (first element of the second line in the file) is multiplied by the size of the elements (8 for floats, 4 for strings and so on) and the allocated memory gets overflowed when the elements are copied one by one. At the moment I have not seen ways to exploit this vulnerability to execute code so I report it just as reference.
Both the A and B problems are exploitable with the CY3 ("StatXact 5.0 data") and CYL ("LogXact data") files.
Stack overflow in the handling of the USE command of the CYB files.
=========== 3) The Code ===========
====== 4) Fix ======
Luigi Auriemma http://aluigi.org