Posts

Showing posts from March, 2021

Como resetear password root en Ubuntu

Image
 Para hacer un reset de password root de Ubuntu, seguir estos pasos. Se requiere acceso por consola o similar a la máquina. Reiniciar el servidor manteniendo la tecla SHIFT presionada, esto permitirá mostrar el menú GRUB Una vez en el menú, seleccionar la primera entrada y presionar la tecla "e" para poder entrar al menú de edición. En el menú de edición, bajar con el teclado hasta la sección que dice linux /boot/vmlinuz ... Eliminar la última parte de la sección que dice algo similar a "ro quiet splash $vt_handoff".En este caso dice algo diferente, pero el propósito de la línea es el modo Read Only, por eso dice "ro". Cambiar esa parte del texto, eliminando lo que diga "ro ....asdfasdf" por "rw init=/bin/bash" Sin las comillas obviamente. Presionar F10 para guardar e iniciar. El sistema iniciará sin password Se puede ejecutar el siguiente comando para validar el acceso de escritura mount | grep -w / Luego se puede hacer el cambio de pa

HAFNIUM zero-day exploit Microsoft Exchange on-premises (02-march 2021)

 Hi, Microsoft has detected multiple 0-day exploits against on-premises Exchange servers. This attack has been attributed to a group under name "HAFNIUM" You can find more information about this group in this blog: New nation-state cyberattacks - Microsoft On the Issues So, Microsoft is recomending to install updates on all versions of exposed Exchange servers. This vulnerability does not affect Exchange Online. Any Exchange server on-premises who is publishing HTTPS on internet is a target.  Please follow Microsoft guide for updating your servers: 1. Download this script to check vulnerability status of your servers from Github 2. Download the required Software patch for your server version/edition. (check the requirements!) Exchange Server 2010 (update requires Service Pack 3 – this is a Defense in Depth update) Exchange Server 2013 (update requires CU 23) Exchange Server 2016 (update requires CU 19 or CU 18) Exchange Server 2019 (update requires CU 8 or CU 7) 3. Put your s

Error 'General access denied error' (0x80070005). Starting SCVMM Resource

Image
 Hello,  After a VMM migration and disk migration I faced this issue. I was unable to start a VM. So if you check on Failover Cluster Manager, you should find this information under "roles". If you check information, it says you should get more information from the "Information Details" windows. This example error says about an Access denied error, so this should be related to permisions. In fact, I did a change on my VMs disk, that is probably the cause on my case.  For resolving I recommend, checking on permissions on the disks of your VM, and if possible, use a tool to copy/paste the correct permissions. Luckly in my case, I do have another disk with the correct permissions, so I used icacls to backup and restore the correct permissions. icacls VM1_mydisk.vhdx /save backup.txt then, you should open the backup.txt file and change the name of the file, to match the destination. then restore using: icacls C:\ClusterStorage\Volume3\VM1 /restore backup.txt After doing