Spark Hybrid Calendar ServiceApplication · Cisco
CVE-2017-12310
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 in the auto discovery phase of Cisco Spark Hybrid Calendar Service could allow an unauthenticated, remote attacker to view sensitive information in the unencrypted headers of an HTTP method request. The attacker could use this information to conduct additional reconnaissance attacks leading to the disclosure of sensitive customer data. The vulnerability exists in the auto discovery phase because an unencrypted HTTP request is made due to requirements for implementing the Hybrid Calendar service. An attacker could exploit this vulnerability by monitoring the unencrypted traffic on the network. An exploit could allow the attacker to access sensitive customer data belonging to Office365 users, such as email and calendar events. Cisco Bug IDs: CSCvg35593.
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 confidenceThis vulnerability exists in the auto discovery phase of Cisco Spark Hybrid Calendar Service, which transmits sensitive customer data in unencrypted HTTP headers. An unauthenticated remote attacker positioned on the network can monitor this plaintext traffic to intercept Office365 user data including email addresses and calendar event information. The issue stems from the service requirement implementation that does not enforce encryption during the auto discovery process.
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
Spark Hybrid Calendar ServiceApplication
all 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
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
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 Cisco Spark Hybrid Calendar Service is deployedReview installed software or service inventory for 'Cisco Spark Hybrid Calendar Service' or check the Cisco Spark/Hybrid services documentation for your organizationAffected if The service is present and operational in the environment
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Confirm auto discovery feature is enabledCheck service configuration for auto discovery settings, typically found in the hybrid calendar service admin interface or configuration filesAffected if Auto discovery is enabled and configured to connect to Office365
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Verify encryption protocol used during auto discoveryInspect network traffic or proxy logs during auto discovery phase for HTTP requests on port 80, or check service configuration for TLS/SSL enforcement settingsAffected if HTTP (unencrypted) is used instead of HTTPS for auto discovery requests
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Inspect HTTP headers for sensitive Office365 dataCapture or review network traffic during auto discovery and examine headers for plaintext email addresses, calendar event identifiers, or user principal namesAffected if Sensitive Office365 user data such as email addresses or calendar information appears in plaintext HTTP headers
If Cisco Spark Hybrid Calendar Service is running with auto discovery enabled and traffic is unencrypted (HTTP), the environment is vulnerable to interception of Office365 user data.
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 dataApply the vendor patch from Cisco (Bug ID CSCvg35593). Until patched, network monitoring and segmentation may help detect traffic interception attempts. The fix requires ensuring all auto discovery HTTP requests use TLS/SSL encryption.
Fix this in Spark Hybrid Calendar Service
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2017-12310 — 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-2017-12310 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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- Version or environment caveats, and links to real fixes
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