Description

Out-of-bounds write in .NET allows an unauthorized attacker to execute code locally.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.8",
  "pubDate": "2026-08-11T17:18:37.843Z",
  "pubdate": "2026-08-11T17:18:37.843Z",
  "executiveSummary": "An out-of-bounds write vulnerability has been identified within .NET, representing a critical security flaw that poses significant risks to system integrity and confidentiality.\nThe vulnerability type is classified as an out-of-bounds write, which fundamentally allows unauthorized local attackers to execute arbitrary code within the context of the affected application.\nThe affected product is .NET, impacting systems relying on vulnerable runtime environments.\nThe risk implications are severe, as successful exploitation could lead to local code execution, potentially allowing threat actors to elevate privileges, compromise sensitive data, or fully takeover the host system.\nAttacker capabilities require local access to the target system to successfully trigger the flaw and execute unauthorized payloads.\nExploitation requirements depend on the attacker's ability to interact with the vulnerable component locally, leveraging the memory corruption primitive to achieve arbitrary code execution without requiring prior authentication or elevated privileges beyond local execution capabilities.",
  "technicalDetails": "The root cause of this vulnerability stems from an out-of-bounds write flaw in .NET, wherein the memory management logic fails to properly validate index boundaries or buffer sizes during memory write operations.\nThe vulnerable component resides within the core memory handling and execution subsystems of .NET, which processes specific data structures incorrectly.\nAffected versions include vulnerable releases of .NET where bounds checking is insufficiently enforced, creating conditions where data can be written past the allocated buffer boundaries.\nAuthentication requirements are absent, meaning an unauthorized user with local access can initiate the attack sequence.\nPrivilege requirements are minimal, as local execution capabilities are sufficient to interact with the vulnerable runtime or application.\nNetwork exposure is not strictly required for exploitation, as the vulnerability is triggered locally, though it may be leveraged via remote vectors if application logic exposes the vulnerable interface.\nThe exploitation method involves supplying maliciously crafted inputs or leveraging specific API interactions that trigger the out-of-bounds write condition within the memory space.\nThe attack flow proceeds as follows: First, the local attacker initiates execution of a specially crafted payload or application designed to interact with the vulnerable .NET component. Second, the component processes the input without adequate bounds validation, resulting in an out-of-bounds write primitive. Third, the attacker overwrites adjacent memory structures, control flow data, or critical application pointers. Finally, the corrupted memory state alters execution flow, allowing the attacker to execute arbitrary native or managed code.\nPayload behavior centers on leveraging the memory corruption to hijack control flow, inject shellcode, or perform unauthorized modifications to system memory.\nPost-exploitation impact includes complete local system compromise, arbitrary code execution with the permissions of the running .NET process, privilege escalation, and potential lateral movement or persistence establishment within the environment."
}