CVE-2016-20033Public exploit

LocalSystem execution via writable service binaries

Published Mar 15, 2026 · Updated Mar 15, 2026

Local privilege escalation in Wowza Streaming Engine 4.5.0 allows local users to execute code as LocalSystem on Windows. The Windows installer grants Everyone full control over nssm_x64.exe in both engine and manager service directories, permitting binary replacement. Exploitation requires local authenticated access and takes effect when either affected service restarts under LocalSystem.

CVSS severity8.5
High
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Local privilege escalation in Wowza Streaming Engine 4.5.0 allows local users to execute code as LocalSystem on Windows. The Windows installer grants Everyone full control over nssm_x64.exe in both engine and manager service directories, permitting binary replacement. Exploitation requires local authenticated access and takes effect when either affected service restarts under LocalSystem.

The record

CVE
CVE-2016-20033
Published
Mar 15, 2026
Updated
Mar 15, 2026
Vendor
Wowza Media Systems
Product
Wowza Streaming Engine
Classifications
CWE-639, T1574.010
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.5.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Wowza Media Systems · Wowza Streaming Engineversion=4.5.0

Published CVSS scores

8.5VulnCheckCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
7.8VulnCheckCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-639Authorization Bypass Through User-Controlled Key
T1574.010Services File Permissions Weakness

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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