Description

Null pointer dereference in Windows TCP/IP allows an unauthorized attacker to deny service over a network.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.5",
  "pubDate": "2026-08-11T17:18:07.430Z",
  "pubdate": "2026-08-11T17:18:07.430Z",
  "executiveSummary": "This vulnerability is classified as a null pointer dereference affecting the Windows TCP/IP protocol stack. The primary impact of this security flaw is a denial of service condition, which can disrupt critical network operations and render affected systems unresponsive over a network interface. The affected product encompasses the Windows operating system TCP/IP implementation. The risk implications are severe for enterprise environments relying on continuous network availability, as unexpected system crashes can lead to operational downtime and service degradation.\nThe attacker capabilities required to exploit this vulnerability are relatively low in terms of privileges, as the input explicitly notes that an unauthorized attacker can execute the attack. Regarding exploitation requirements, the attacker must possess network connectivity to the target system to transmit malicious or malformed network packets that trigger the flawed condition within the protocol stack. No prior authentication or specialized credentials are required to initiate the attack sequence, increasing the overall threat level for externally exposed interfaces or unsegmented internal networks.",
  "technicalDetails": "The vulnerability resides within the Windows TCP/IP component, specifically in how the protocol stack handles incoming network packets or specific state transitions. The root cause of a null pointer dereference occurs when the software attempts to dereference a pointer that has a NULL value, assuming it points to a valid memory location. In the context of the Windows TCP/IP stack, this typically happens when packet parsing logic or connection state management fails to adequately validate the existence or initialization of internal data structures before attempting to access or manipulate them.\nThe attack flow begins when an unauthorized remote attacker crafts and transmits a specifically designed sequence of network packets targeted at the vulnerable Windows system utilizing the TCP/IP protocol. Upon receipt, the Windows networking stack processes the incoming payload. Due to missing input validation or improper error handling during packet dissection or connection teardown/establishment phases, the internal function handling the routine encounters an unexpected condition and assigns a null value to a critical pointer instead of allocating or referencing the expected memory object.\nWhen the execution flow subsequently attempts to read from or write to this null-assigned pointer, the operating system's memory management unit triggers an unhandled access violation. Because this critical failure occurs within kernel-mode drivers associated with core networking functionality, the operating system cannot gracefully recover from the exception. Consequently, this results in a kernel crash, commonly observed as a Blue Screen of Death, thereby achieving the denial of service state. The vulnerability is exposed over the network, meaning any remote node capable of communicating with the target's TCP/IP stack can potentially initiate the payload behavior, resulting in immediate service interruption and complete loss of availability for the targeted host."
}