type: attack-pattern
spec_version: 2.1
id: attack-pattern--01327cde-66c4-4123-bf34-5f258d59457b
created: 2020-02-11T18:28:44.950Z
created_by_ref: identity--c78cb6e5-0c4b-4611-8297-d1b8b55e40b5
revoked: no
external_references: source_name: mitre-attack
url: https://attack.mitre.org/techniques/T1021/005
external_id: T1021.005
source_name: Attacking VNC Servers PentestLab
description: Administrator, Penetration Testing Lab. (2012, October 30). Attacking VNC Servers. Retrieved October 6, 2021.
url: https://pentestlab.blog/2012/10/30/attacking-vnc-servers/
source_name: MacOS VNC software for Remote Desktop
description: Apple Support. (n.d.). Set up a computer running VNC software for Remote Desktop. Retrieved August 18, 2021.
url: https://support.apple.com/guide/remote-desktop/set-up-a-computer-running-vnc-software-apdbed09830/mac
source_name: Havana authentication bug
description: Jay Pipes. (2013, December 23). Security Breach! Tenant A is seeing the VNC Consoles of Tenant B!. Retrieved September 12, 2024.
url: https://lists.openstack.org/pipermail/openstack/2013-December/004138.html
source_name: macOS root VNC login without authentication
description: Nick Miles. (2017, November 30). Detecting macOS High Sierra root account without authentication. Retrieved September 20, 2021.
url: https://www.tenable.com/blog/detecting-macos-high-sierra-root-account-without-authentication
source_name: Offensive Security VNC Authentication Check
description: Offensive Security. (n.d.). VNC Authentication. Retrieved October 6, 2021.
url: https://www.offensive-security.com/metasploit-unleashed/vnc-authentication/
source_name: Gnome Remote Desktop grd-settings
description: Pascal Nowack. (n.d.). Retrieved September 21, 2021.
url: https://gitlab.gnome.org/GNOME/gnome-remote-desktop/-/blob/9aa9181e/src/grd-settings.c#L207
source_name: Gnome Remote Desktop gschema
description: Pascal Nowack. (n.d.). Retrieved September 21, 2021.
url: https://gitlab.gnome.org/GNOME/gnome-remote-desktop/-/blob/9aa9181e/src/org.gnome.desktop.remote-desktop.gschema.xml.in
source_name: Apple Unified Log Analysis Remote Login and Screen Sharing
description: Sarah Edwards. (2020, April 30). Analysis of Apple Unified Logs: Quarantine Edition [Entry 6] – Working From Home? Remote Logins. Retrieved August 19, 2021.
url: https://sarah-edwards-xzkc.squarespace.com/blog/2020/4/30/analysis-of-apple-unified-logs-quarantine-edition-entry-6-working-from-home-remote-logins
source_name: VNC Vulnerabilities
description: Sergiu Gatlan. (2019, November 22). Dozens of VNC Vulnerabilities Found in Linux, Windows Solutions. Retrieved September 20, 2021.
url: https://www.bleepingcomputer.com/news/security/dozens-of-vnc-vulnerabilities-found-in-linux-windows-solutions/
source_name: The Remote Framebuffer Protocol
description: T. Richardson, J. Levine, RealVNC Ltd.. (2011, March). The Remote Framebuffer Protocol. Retrieved September 20, 2021.
url: https://datatracker.ietf.org/doc/html/rfc6143#section-7.2.2
source_name: VNC Authentication
description: Tegan. (2019, August 15). Setting up System Authentication. Retrieved September 20, 2021.
url: https://help.realvnc.com/hc/en-us/articles/360002250097-Setting-up-System-Authentication
source_name: Hijacking VNC
description: Z3RO. (2019, March 10). Day 70: Hijacking VNC (Enum, Brute, Access and Crack). Retrieved September 20, 2021.
url: https://int0x33.medium.com/day-70-hijacking-vnc-enum-brute-access-and-crack-d3d18a4601cc
object_marking_refs: marking-definition--fa42a846-8d90-4e51-bc29-71d5b4802168
modified: 2025-10-24T17:48:19.567Z
name: VNC
description: Adversaries may use [Valid Accounts](https://attack.mitre.org/techniques/T1078) to remotely control machines using Virtual Network Computing (VNC). VNC is a platform-independent desktop sharing system that uses the RFB (“remote framebuffer”) protocol to enable users to remotely control another computer’s display by relaying the screen, mouse, and keyboard inputs over the network.(Citation: The Remote Framebuffer Protocol)

VNC differs from [Remote Desktop Protocol](https://attack.mitre.org/techniques/T1021/001) as VNC is screen-sharing software rather than resource-sharing software. By default, VNC uses the system's authentication, but it can be configured to use credentials specific to VNC.(Citation: MacOS VNC software for Remote Desktop)(Citation: VNC Authentication)

Adversaries may abuse VNC to perform malicious actions as the logged-on user such as opening documents, downloading files, and running arbitrary commands. An adversary could use VNC to remotely control and monitor a system to collect data and information to pivot to other systems within the network. Specific VNC libraries/implementations have also been susceptible to brute force attacks and memory usage exploitation.(Citation: Hijacking VNC)(Citation: macOS root VNC login without authentication)(Citation: VNC Vulnerabilities)(Citation: Offensive Security VNC Authentication Check)(Citation: Attacking VNC Servers PentestLab)(Citation: Havana authentication bug)
kill_chain_phases: kill_chain_name: mitre-attack
phase_name: lateral-movement
x_mitre_attack_spec_version: 3.2.0
x_mitre_deprecated: no
x_mitre_domains: enterprise-attack
x_mitre_is_subtechnique: yes
x_mitre_modified_by_ref: identity--c78cb6e5-0c4b-4611-8297-d1b8b55e40b5
x_mitre_platforms: Linux
Windows
macOS
x_mitre_version: 1.2