Description

Heap-based buffer overflow in Windows DHCP Client allows an authorized attacker to elevate privileges locally.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.8",
  "pubDate": "2026-08-11T17:18:25.217Z",
  "pubdate": "2026-08-11T17:18:25.217Z",
  "executiveSummary": "This vulnerability is a heap-based buffer overflow affecting the Windows DHCP Client. The primary security impact of this flaw is local privilege escalation, allowing an authorized threat actor to execute arbitrary code with elevated privileges on targeted systems.\nThe affected product is the Windows DHCP Client service responsible for managing network configuration parameters. The risk implications are severe, as a successful exploitation compromises the confidentiality, integrity, and availability of the underlying operating system.\nAttacker capabilities require local access to the system with authorization to interact with the vulnerable client interface. Exploitation requirements mandate that the attacker possesses prior execution capability on the local host to deliver and trigger the malicious payload against the DHCP client component.",
  "technicalDetails": "The root cause of the vulnerability is a heap-based buffer overflow located within the Windows DHCP Client. This memory corruption flaw manifests when the vulnerable component improperly validates the size and boundaries of dynamic memory allocations during the processing of DHCP message parameters or configuration responses.\nThe vulnerable component is the DHCP client service handling network state logic and message parsing routines. The attack vector is strictly local, requiring the attacker to execute code within the context of the operating system and interact with the local DHCP client functionality.\nAuthentication requirements dictate that the attacker must be an authorized local user, while the privilege requirements are constrained to standard user access prior to exploitation. The vulnerability does not present direct network exposure for remote exploitation based on the provided input description.\nThe step-by-step attack flow begins with the local attacker crafting a specially constructed input or manipulating internal data structures intended for the Windows DHCP Client. When the vulnerable function processes this malformed input, it fails to enforce adequate bounds checking on the destination heap buffer.\nConsequently, the input overflows the allocated heap chunk, corrupting adjacent memory structures, heap metadata, or function pointers. By carefully controlling the overflow data, the attacker can overwrite critical memory regions with shellcode or redirected execution pointers.\nThe payload behavior involves hijacking control flow to execute arbitrary instructions in the context of a privileged system account or service context. The post-exploitation impact includes complete local privilege escalation, granting the attacker administrative control over the compromised Windows operating system."
}