Application: Pidgin 2.4.1 OS: Linux - Ubuntu 8.04 ------------------------------------------------------ 1 - Description 2 - Vulnerability 3 - POC/EXPLOIT ------------------------------------------------------ Description Pidgin is an instant messaging program with which you can use a number of protocols known as (MSN, ICQ, AIM). While there is Pidgin 2.4.2 version which was not provided in this version so I could not say whether it was also vulnerable. ------------------------------------------------------ Vulnerability The vulnerability works sending files with the protocol msn (I did not test at all protocols), if a file is sent with a long name and special characters and this causes the program to break. If we analyze the vulnerability with a debugger you can see a flaw in the following function 0xb62abaeb in msn_slplink_process_msg According with the characters used, the fault may vary in other functions. ------------------------------------------------------ POC/EXPLOIT For proof of the concept you should create a file either (never mind the extension) with the maximum allowable characters, with the following characteristics. ASCII = (‣ ․ ‥ ? ) HEX = ( 26 23 38 32 32 37 3b 20 26 23 38 32 32 38 3b 20 26 23 38 32 32 39 3b 20 85 ) ------------------------------------------------------ Juan Pablo Lopez Yacubian