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HighCISA KEVExploited in the wildPublic exploit

Secondary Logon Elevation of Privilege Vulnerability

IdentifiersCVE-2016-0099CWE-20

CVE-2016-0099 is a local elevation-of-privilege vulnerability in the Microsoft Windows Secondary Logon Service affecting Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, and Windows 10 Gold and 1511. The flaw exists because the Secondary Logon Service does not properly process request handles. A local attacker can exploit this weakness by running a crafted application that abuses the service’s improper handle processing to elevate privileges on the affected system. The vulnerability is referred to by Microsoft as the "Secondary Logon Elevation of Privilege Vulnerability."

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows a local user to gain elevated privileges on the target Windows host. In practical terms, this can enable execution of code with higher integrity or administrative/SYSTEM-level rights, facilitating post-compromise actions such as disabling security controls, credential theft, persistence, lateral movement preparation, and deployment of additional malware or ransomware.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, reduce exposure by limiting local code execution opportunities, enforcing least privilege for user accounts, restricting interactive logon to trusted users, and monitoring for suspicious use of privilege-escalation tooling or crafted binaries targeting the Secondary Logon Service. Application allowlisting, EDR telemetry on abnormal seclogon-related activity, and rapid containment of initial access can reduce the likelihood of successful exploitation, but these measures do not fully remediate the flaw.

Remediation

Patch, then assume compromise.

Apply the Microsoft security update that addresses CVE-2016-0099 on all affected Windows systems. Priority should be given to legacy and unsupported systems still running the listed vulnerable versions. Standard remediation should include verifying patch deployment across endpoints and servers, retiring unsupported operating systems where possible, and ensuring local privilege-escalation exploit protections and endpoint monitoring remain enabled.
PUBLIC EXPLOITS

Exploits

1 valid exploit after Mallory filtered fakes, detection scripts, and README-only repos (3 hidden).

VALID 1 / 4 TOTALView more in app
MS16-032MaturityPoCVerified exploit

This repository contains a Visual Studio project for an exploit targeting MS16-032 (CVE-2016-0099), a Windows privilege escalation vulnerability. The structure includes a solution file, project files, and references to a main C++ source file (ms16-032.cpp), which is not included in the provided content. The README specifies that the exploit is intended for use in a service context, indicating it must be run as a Windows service to function. The project is configured for both 32-bit and 64-bit Windows builds. No network endpoints or external IPs are present; the attack vector is local privilege escalation. The repository is a proof-of-concept (POC) for local exploitation and does not appear to be weaponized or part of a larger framework. The main fingerprintable endpoint is the source file path for the exploit code.

zcgonvhDisclosed Mar 15, 2017cppxmllocal
EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
Microsoft CorporationWindows 10 1507operating_system
Microsoft CorporationWindows 10 1511operating_system
Microsoft CorporationWindows 7operating_system
Microsoft CorporationWindows 8.1operating_system
Microsoft CorporationWindows Server 2008operating_system
Microsoft CorporationWindows Server 2012operating_system
Microsoft CorporationWindows Vistaoperating_system

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.
Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware4

Malware families riding this exploit, with evidence and IOCs.

Detection signatures1

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity

Community discussion across Reddit, Mastodon, and other social sources.