CVE-2000-0983 in Netmeeting
Summary
by MITRE
Microsoft NetMeeting with Remote Desktop Sharing enabled allows remote attackers to cause a denial of service (CPU utilization) via a sequence of null bytes to the NetMeeting port, aka the "NetMeeting Desktop Sharing" vulnerability.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 02/17/2025
The CVE-2000-0983 vulnerability represents a critical denial of service flaw in Microsoft NetMeeting software that specifically affects systems with Remote Desktop Sharing enabled. This vulnerability operates through a carefully crafted sequence of null bytes transmitted to the NetMeeting port, causing significant system instability and resource exhaustion. The flaw stems from inadequate input validation within the NetMeeting desktop sharing component, which fails to properly handle malformed data sequences that include null byte characters. This vulnerability was particularly concerning as NetMeeting was widely deployed in corporate environments for remote collaboration and desktop sharing purposes, making it an attractive target for malicious actors seeking to disrupt business operations.
The technical exploitation of this vulnerability occurs when an attacker sends a specific sequence of null bytes to the NetMeeting service port, typically port 1433 or other designated sharing ports. The vulnerability manifests as excessive cpu utilization as the NetMeeting service attempts to process the malformed input, leading to system resource exhaustion and complete service unavailability. The flaw exists in the protocol handling logic where the application does not properly validate or sanitize incoming data streams before processing them, allowing the null byte sequence to trigger an infinite loop or resource-consuming processing routine. This behavior aligns with CWE-129, Input Validation, and CWE-400, Uncontrolled Resource Consumption, as the vulnerability exploits improper input handling to cause resource exhaustion.
The operational impact of this vulnerability extends beyond simple service disruption to encompass broader business continuity concerns. Organizations relying on NetMeeting for remote desktop sharing and collaboration would experience immediate service outages that could affect productivity and remote work capabilities. The vulnerability is particularly dangerous in enterprise environments where NetMeeting might be configured to allow external connections or where multiple users might be accessing shared desktop resources. Attackers could leverage this flaw to repeatedly cause service disruptions, potentially leading to extended downtime and loss of critical business operations. The vulnerability also demonstrates the risks associated with legacy remote desktop solutions and highlights the importance of proper input sanitization in network services, which corresponds to ATT&CK technique T1499.004, Network Denial of Service.
Mitigation strategies for this vulnerability primarily involve immediate patching of affected Microsoft NetMeeting installations through official security updates from Microsoft. Organizations should disable Remote Desktop Sharing functionality when not actively required and implement network segmentation to limit access to NetMeeting ports. Additionally, network monitoring should be enhanced to detect unusual patterns of null byte traffic directed toward known NetMeeting service ports. System administrators should consider implementing rate limiting and connection throttling mechanisms to prevent abuse of the vulnerable service. The remediation process should include comprehensive testing of patched systems to ensure that the vulnerability is fully resolved without introducing compatibility issues with existing network configurations. This vulnerability underscores the critical importance of maintaining up-to-date security patches and implementing proper network access controls to prevent exploitation of known vulnerabilities in remote desktop services.