X11 Unauthenticated Access Scanner
This scanner detects the use of X11 Unauthenticated Access in digital assets. It identifies open X11 servers that may allow unauthorized connections, ensuring potential security risks are addressed.
Short Info
Level
High
Single Scan
Single Scan
Can be used by
Asset Owner
Estimated Time
10 seconds
Time Interval
11 days 2 hours
Scan only one
Domain, IPv4, Subdomain
Toolbox
-
The software X11, or X Window System, is a windowing system for bitmap displays, commonly used on UNIX-like operating systems. It is implemented by a display server that processes graphical display requests and inputs. X11 is utilized by system administrators and developers to enable graphical user interface access on networked systems. The platform supports multiple client–server configurations, offering flexibility in networked environments. X11 is foundational for GUI interactions on many Linux-based systems, often serving as the underlying protocol for desktop environments and applications. Secure configuration of X11 is vital to prevent unauthorized access, which could compromise system security.
Unauthenticated Access vulnerability in X11 involves the ability of unauthorized users to connect to the X server. This vulnerability arises when access controls are not properly configured, allowing any remote connection attempts. Insecure configurations can expose sensitive graphical data or control over the X11 display to attackers. Vulnerable systems may unwittingly provide attackers the ability to intercept user inputs or modify displayed outputs. Ensuring proper authentication and connection management is crucial to mitigating unauthorized access risks. Organizations need to regularly audit their X11 configurations to ensure compliance with security best practices.
The vulnerability occurs due to improper access controls on TCP port 6000+n, where n represents the display number of the X server. Attackers may attempt to connect using an initial X11 connection request, bypassing authentication mechanisms if improperly configured. The X server's response indicates whether access is granted or denied. A positive response allows attackers to eavesdrop on display data or inject malicious commands, potentially compromising the entire system. Ensuring secure port configurations and restricting access to trusted IPs can help mitigate this vulnerability. Immediate review of network security policies is recommended to enforce robust X11 authentication measures.
When exploited, this vulnerability could allow attackers to gain direct access to the graphical interface of remote systems. Attackers could monitor user activity, intercept sensitive data, or execute malicious commands. System compromise could lead to unauthorized data access, modification, or destruction. Exploited systems may serve as entry points for further intrusions into the network. Additionally, such vulnerabilities risk non-compliance with security standards, exposing organizations to potential legal liabilities. Securing X11 configurations proactively is critical in maintaining the integrity and confidentiality of system operations.
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