Description

Integer overflow or wraparound in .NET allows an unauthorized attacker to elevate privileges locally.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.8",
  "pubDate": "2026-08-11T17:18:39.717Z",
  "pubdate": "2026-08-11T17:18:39.717Z",
  "executiveSummary": "An integer overflow or wraparound vulnerability has been identified within .NET, posing a severe security risk to affected systems.\nThis vulnerability specifically enables an unauthorized local attacker to successfully elevate privileges, transitioning from low-privilege execution contexts to higher, potentially administrative levels.\nThe flaw resides in the core architectural components of .NET, impacting systems executing unmitigated runtimes where integer boundary conditions are improperly validated during arithmetic operations.\nThe risk implications are significant, as successful exploitation allows local threat actors to bypass security controls, execute arbitrary code with elevated permissions, and potentially compromise the integrity and confidentiality of the host operating system.\nAttacker capabilities are constrained primarily by the requirement for local access, meaning the adversary must already possess execution privileges on the target machine to deliver and trigger the malicious payload.\nExploitation requirements include interacting with the vulnerable .NET component via specially crafted inputs designed to induce an integer wraparound condition, thereby subverting memory safety or access control checks that rely on the affected calculations.",
  "technicalDetails": "The root cause of this vulnerability stems from insecure arithmetic operations within .NET where integer values exceed their maximum storable limits without adequate boundary checks or overflow handling.\nWhen an arithmetic operation results in an integer overflow or wraparound, the resulting value wraps around to a small integer or a negative number, which can then be mishandled by downstream logic responsible for memory allocation, buffer sizing, or permission validation.\nThe vulnerable component involves internal routines within .NET that process size calculations or resource allocation metrics.\nAuthentication and privilege requirements dictate that the attacker must have local interactive or programmatic access to the host environment, functioning as an unprivileged user prior to exploitation.\nNetwork exposure is not strictly required for initial access, as this is a local privilege escalation vector; however, remote access vectors could theoretically chain into this vulnerability if an exposed service interacts with the vulnerable local .NET subsystem using untrusted data.\nThe attack flow begins when the local attacker supplies maliciously crafted input—such as an oversized parameter or array length—to a .NET application or service running locally.\nThis input forces an integer overflow during internal calculations within the vulnerable .NET component.\nBecause the runtime fails to properly detect or handle the wraparound condition, subsequent memory operations allocate insufficient buffer space or incorrectly evaluate authorization boundaries based on the corrupted integer value.\nThis state corruption leads to memory corruption conditions, such as heap-based or stack-based buffer overflows, or logic flaws that prematurely grant administrative privileges to the calling execution context.\nPayload behavior following successful exploitation typically involves spawning a command shell or injecting malicious payloads into privileged system processes.\nThe post-exploitation impact includes complete local system compromise, persistent unauthorized access, capability to modify sensitive system configurations, and potential lateral movement within the network if the compromised host is utilized as a pivot point."
}