CVE-2021-32198
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 · uneditedEmTec ZOC through 8.02.4 allows remote servers to cause a denial of service (Windows GUI hang) by telling the ZOC window to change its title repeatedly at high speed, which results in many SetWindowTextA or SetWindowTextW calls. In other words, it does not implement a usleep or similar delay upon processing a title change.
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 confidenceEmTec ZOC terminal emulator through 8.02.4 lacks rate limiting on title change processing. A malicious remote server can send repeated OSC title change sequences at high speed, causing excessive SetWindowTextA/SetWindowTextW calls that hang the Windows GUI.
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<= 8.02.4CVSS 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
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/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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Confirm EmTec ZOC is installedLook for ZOC terminal emulator in the Start Menu, Program Files folder, or check Add/Remove Programs for 'EmTec ZOC'Affected if EmTec ZOC is present on the system
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Identify the installed ZOC versionOpen ZOC and navigate to Help > About, or right-click the ZOC executable, select Properties, and check the File Version fieldAffected if The version number displayed is 8.02.4 or lower
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Check for recent ZOC usage with remote connectionsReview saved session logs or connection history to identify if ZOC has been used to connect to remote SSH/Telnet/Raw serversAffected if ZOC has connected to remote servers, particularly untrusted or unknown ones
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Verify the GUI hang symptomIf ZOC becomes unresponsive after connecting to a remote server that sends rapid title changes, this indicates the vulnerability is triggeredAffected if The GUI hangs or freezes during or after a remote connection session with rapid title updates
You are affected if EmTec ZOC version 8.02.4 or lower is installed and has been used to connect to remote servers that can send OSC title change sequences.
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 dataUpdate to patched version when available; avoid connecting to untrusted/unknown remote servers until patched.
- Consultation2.0 h
- Implementation4.0 h
- Testing4.0 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 $3,328.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-32198 — 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-2021-32198 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
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