CVE-2021-28821
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedThe Windows Installation component of TIBCO Software Inc.'s TIBCO Enterprise Message Service, TIBCO Enterprise Message Service - Community Edition, and TIBCO Enterprise Message Service - Developer Edition contains a vulnerability that theoretically allows a low privileged attacker with local access on some versions of the Windows operating system to insert malicious software. The affected component can be abused to execute the malicious software inserted by the attacker with the elevated privileges of the component. This vulnerability results from a lack of access restrictions on certain files and/or folders in the installation. Affected releases are TIBCO Software Inc.'s TIBCO Enterprise Message Service: versions 8.5.1 and below, TIBCO Enterprise Message Service - Community Edition: versions 8.5.1 and below, and TIBCO Enterprise Message Service - Developer Edition: versions 8.5.1 and below.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThe Windows installer for TIBCO Enterprise Message Service creates files and folders with overly permissive access controls, allowing a low-privileged local attacker to insert malicious executables into the installation directory. When the affected component runs, it executes these attacker-controlled files with elevated (SYSTEM) privileges, achieving local privilege escalation.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data<= 8.5.1CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify if TIBCO EMS is installedCheck the Windows Registry under HKLM\SOFTWARE\TIBCO for the EMS installation path, or look for 'tibco' folders in Program Files or Program Files (x86)Affected if The software is found and the version is 8.5.1 or below
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Determine the installed EMS versionRun 'tibemsd -version' from the EMS bin directory, or check the version field in the README or about file within the installation folderAffected if Version is 8.5.1 or any version <= 8.5.1
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Examine folder permissions on the EMS installation directoryRight-click the EMS installation folder, go to Properties > Security, and review the permissions for Users and Authenticated Users groupsAffected if Users or Authenticated Users have Write or Modify permissions to the main EMS folder or subfolders containing executables
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Check for weak ACLs on EMS executable directoriesUse icacls.exe (e.g., 'icacls "C:\Program Files\TIBCO\ems\bin"') to list all permissions, looking for entries granting Write or Create permissions to non-admin usersAffected if Non-privileged user accounts or the Users group are granted Write, CreateFiles, or Modify access to folders containing tibemsd.exe or other EMS executables
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Audit the EMS bin folder for unauthorized executablesList all .exe and .dll files in the EMS bin directory (e.g., 'dir /a C:\Program Files\TIBCO\ems\bin') and verify they are legitimate TIBCO filesAffected if Any unexpected executables exist in the bin folder that were not installed by TIBCO, or the folder is writable by low-privilege users
A system is affected if TIBCO Enterprise Message Service version 8.5.1 or lower is installed and non-administrator users have write permissions to the EMS installation directories containing executables.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataRestrict file system permissions on the TIBCO EMS installation directory to prevent unauthorized modification by non-admin users; upgrade to a patched version if available from TIBCO.
- Consultation3.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,168.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-28821 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-28821 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data