A xine security announcement reports:
By a user receiving data from a malicious network streaming server, an attacker can overrun a heap buffer, which can, on some systems, lead to or help in executing attacker-chosen malicious code with the permissions of the user running a xine-lib based media application. Both the MMS and Real RTSP streaming client code made some too-strong assumptions on the transferred data. Several critical bounds checks were missing, resulting in the possibility of heap overflows, should the remote server not adhere to these assumptions. In the MMS case, a remote server could present content with too many individual streams; in the RTSP case, a remote server's reply could have too many lines. An attacker can set up a server delivering malicious data to the users. This can be used to overflow a heap buffer, which can, with certain implementations of heap management, lead to attacker chosen data written to the stack. This can cause attacker-chosen code being executed with the permissions of the user running the application. By tricking users to retrieve a stream, which can be as easy as providing a link on a website, this vulnerability can be exploited remotely.