CVE-2021-31891
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 · uneditedA vulnerability has been identified in Desigo CC (All versions with OIS Extension Module), GMA-Manager (All versions with OIS running on Debian 9 or earlier), Operation Scheduler (All versions with OIS running on Debian 9 or earlier), Siveillance Control (All versions with OIS running on Debian 9 or earlier), Siveillance Control Pro (All versions). The affected application incorrectly neutralizes special elements in a specific HTTP GET request which could lead to command injection. An unauthenticated remote attacker could exploit this vulnerability to execute arbitrary code on the system with root privileges.
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 confidenceA command injection vulnerability in the OIS (Open Integration Server) Extension Module across multiple Siemens building management and security products (Desigo CC, GMA-Manager, Operation Scheduler, Siveillance Control, Siveillance Control Pro) allows unauthenticated remote attackers to execute arbitrary code with root privileges via specially crafted HTTP GET requests that improperly neutralize special elements.
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 dataall versionsall versionsall versionsall versionsall versionsCVSS 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
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/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 installed Siemens building management productsReview installed software on the system for any of the following: Siemens Desigo CC, Siemens Siveillance Control Pro, Siemens GMA-Manager, Siemens Operation Scheduler, or Siemens Siveillance Control. Check Windows Programs and Features, Linux package managers, or application directories for these specific product names.Affected if Any of the five affected products (Desigo CC, Siveillance Control Pro, GMA-Manager, Operation Scheduler, or Siveillance Control) is installed on the system
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Locate the OIS Extension ModuleSearch for the OIS (Open Integration Server) Extension Module within the installed product directories or as a running service. Check for processes named ois, ois_extension, or OpenIntegrationServer, and look for configuration files related to OIS extension functionality.Affected if The OIS Extension Module is installed and running as part of the Siemens product
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Verify HTTP service exposureDetermine if the product HTTP interface is accessible from the network. Use netstat or ss commands to check for listening HTTP services on typical ports (such as 8080, 443, 80) associated with the Siemens products, and review firewall rules or network configurations that may allow external access.Affected if The HTTP service listening port is bound to a network-accessible interface (0.0.0.0) rather than localhost only (127.0.0.1)
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Check for suspicious HTTP requests in logsReview web server logs, application logs, and system logs for the affected product. Look for HTTP GET requests containing unusual patterns such as shell metacharacters (| ; & $ ` or command sequences like /bin/sh, cmd.exe) that may indicate exploitation attempts.Affected if Log analysis reveals HTTP GET requests with command injection patterns targeting the OIS Extension Module endpoint
A user is affected if any of the five Siemens building management products with the OIS Extension Module is installed and the HTTP interface is network-accessible, as the vulnerability allows unauthenticated remote command injection via crafted HTTP GET requests.
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 dataImmediately restrict network exposure of affected systems, apply vendor patches from Siemens security advisories, and implement network segmentation to limit attack surface until patches can be deployed.
- Consultation8.0 h
- Implementation12.0 h
- Testing8.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-31891 — 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-2021-31891 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
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