static void t1_check_unusual_charstring(void)
{
    char *p = strstr(t1_line_array, charstringname) + strlen(charstringname);
    int i;
    /* if no number follows "/CharStrings", let's read the next line */
    if (sscanf(p, "%i", &i) != 1) {
        /* pdftex_warn("no number found after `%s', I assume it's on the next line",
                    charstringname); */
        strcpy(t1_buf_array, t1_line_array);

        /* t1_getline always appends EOL to t1_line_array; let's change it to
         * space before appending the next line
         */
         *(strend(t1_buf_array) - 1) = ' ';
 
         t1_getline();
         strcat(t1_buf_array, t1_line_array);
         strcpy(t1_line_array, t1_buf_array);
         t1_line_ptr = eol(t1_line_array);
     }
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.