Description:
| iDefense Security Advisory 05.19.09 - Local exploitation of a file overwrite vulnerability in IBM Corp.'s Advanced Interactive eXecutive (AIX) could allow an attacker to overwrite arbitrary files and execute arbitrary code. The AIX libc implementation of malloc includes a debugging mechanism that is initiated by setting the MALLOCTYPE and MALLOCDEBUG environment variables. This debugging feature writes to a user-specified log file under certain conditions. There is a gap in time between the checks to see if the file is a symbolic link and the process of opening the file. If an attacker can change the file to be a symbolic link to another file within this time frame, it is possible to cause a set-uid binary to write to files owned by privileged users. iDefense confirmed the existence of this vulnerability in IBM Corp.'s AIX version 5.3. Other versions may also be affected. |