SitefinityApplication · Progress

CVE-2017-9248

CRITICAL · 9.8 CVSS v3.1 Published 2017-07-03

Fix available

A fix is available. Upgrade to 10.0.6412.0 or later.

See remediation →

100/100

Remediation priority · Urgent

In the wild High EPSS Public exploit Remotely reachable No privileges Zero-click

Official description

NVD · unedited

Telerik.Web.UI.dll in Progress Telerik UI for ASP.NET AJAX before R2 2017 SP1 and Sitefinity before 10.0.6412.0 does not properly protect Telerik.Web.UI.DialogParametersEncryptionKey or the MachineKey, which makes it easier for remote attackers to defeat cryptographic protection mechanisms, leading to a MachineKey leak, arbitrary file uploads or downloads, XSS, or ASP.NET ViewState compromise.

Technical summary

dbcve analysis · high confidence

The Telerik.Web.UI.dll library in Progress Telerik UI for ASP.NET AJAX and Sitefinity fails to properly protect the DialogParametersEncryptionKey or MachineKey. This allows attackers to derive the cryptographic keys, enabling them to decrypt ViewState, upload or download arbitrary files, and perform XSS attacks.

MitigationUpgrade Telerik UI for ASP.NET AJAX to R2 2017 SP1 or later, and Sitefinity to 10.0.6412.0 or later. Ensure encryption keys are properly secured and rotated if compromise is suspected.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions

NVD · CPE data

SitefinityApplication

Affected:< 10.0.6412.0

Ui For Asp.net AjaxApplication

Affected:<= 2017.2.503

CVSS breakdown

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?

dbcve checks

Work through these to decide whether this CVE applies to you.

Locate Telerik.Web.UI.dll in the application

Search the application bin directory and subdirectories for Telerik.Web.UI.dll. Note the full file path for version inspection.

Affected if The file exists in the application deployment
Check the file version of Telerik.Web.UI.dll

Right-click the DLL file, select Properties, then view the Details tab to see the File Version. Alternatively, use a PowerShell command: (Get-Item 'path\to\Telerik.Web.UI.dll').VersionInfo.FileVersion

Affected if The version displayed is below 2017.2.503 for Telerik UI for ASP.NET AJAX, or below 10.0.6412.0 for Sitefinity
Identify the affected product

Examine the application to determine if it uses Progress Sitefinity or Telerik UI for ASP.NET AJAX components. Check the web.config or project references for Telerik RadControl usage.

Affected if The application is running Sitefinity versions below 10.0.6412.0 or Telerik UI for ASP.NET AJAX versions 2017.2.503 or lower
Verify Telerik async upload handlers are configured

Review the web.config file for the presence of Telerik handler registrations, specifically looking for RadAsyncUpload or Telerik.Web.UI.WebResource.axd configurations.

Affected if Telerik upload handlers are present and the Telerik.Web.UI.dll version is vulnerable
Check for MachineKey exposure risk

Examine if the application uses Telerik encryption utilities and whether the machineKey is stored in web.config in plaintext, as the vulnerability allows key derivation.

Affected if The application uses Telerik cryptographic features with a vulnerable DLL version

The environment is affected if Telerik.Web.UI.dll exists with a version at or below 2017.2.503 (for Telerik UI for ASP.NET AJAX) or below 10.0.6412.0 (for Sitefinity), and the application uses Telerik UI components with upload or encryption features.

Generated from the published advisory. Verify against your own configuration.

Remediation

dbcve · scoped

Upgrade available Upgrade to 10.0.6412.0 or later

Fixed in 10.0.6412.0

Interim mitigation

Upgrade Telerik UI for ASP.NET AJAX to R2 2017 SP1 or later, and Sitefinity to 10.0.6412.0 or later. Ensure encryption keys are properly secured and rotated if compromise is suspected.

Recommended fix High confidence

Telerik UI for ASP.NET AJAX: R2 2017 SP1 (2017.2.621+); Sitefinity: 10.0.6412.0+

1. Identify all deployed instances of Telerik UI for ASP.NET AJAX and Sitefinity in your environment
2. For Telerik UI for ASP.NET AJAX: Upgrade to R2 2017 SP1 (version 2017.2.621 or later) which contains the patched Telerik.Web.UI.dll
3. For Sitefinity: Upgrade to version 10.0.6412.0 or later
4. After upgrading, verify the Telerik.Web.UI.dll version matches the patched release
5. Test critical functionality including file upload/download operations, authentication, and ViewState-dependent features
6. Review and rotate any MachineKey values that may have been exposed, as the vulnerability allows key leakage

Caveat Review Telerik UI for ASP.NET AJAX R2 2017 SP1 release notes for breaking changes in your specific components; Sitefinity 10.0.6412.0 is a patch release with minimal breaking change risk

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Sitefinity Exploited in the wild — priority engagement

Consultation4.0 h
Implementation4.0 h
Testing8.0 h
Review / QA4.0 h

20.0 hours of engineering $3,440

Get it fixed fast

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Scan for this in your stack

Free · runs locally

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References

Primary sources

www.exploit-db.comProof of Concept
www.telerik.comVendor Advisory
www.telerik.comMitigationVendor Advisory
www.securityfocus.comBroken LinkThird Party AdvisoryVDB Entry
www.exploit-db.comExploitThird Party AdvisoryVDB Entry
www.cisa.govUS Government Resource
nvd.nist.govNVD record

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2017-9248 in production — separate from our analysis above.

Notes0 Guidelines

Know something about CVE-2017-9248?

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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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here

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

At a glance

Exploited in the wildOn CISA’s known-exploited list · agencies must fix by 2022-05-03

A fix existsUpgrade to 10.0.6412.0 or later

Severity 9.8 Critical

Exploit likelihood EPSS, next 30 days 75.1%

Affects: Sitefinity

Remediation

Being exploited — close it fast

Fix this in Sitefinity 20 hrs · Moderate

Typical engagement from $3,440

Get it fixed fast See the full breakdown ↓

This CVE is on CISA’s actively-exploited list, so the clock is real — a vetted specialist can deliver a reviewed fix for your staging environment quickly.

You’ll deal with our team directly and deploy the reviewed fix to staging first — never straight to production.

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.

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.

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.

CVSS 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.

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.

Check your environment

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.

Scan for this in your stack

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Practitioner notes

No notes yet

Official description

Technical summary

Affected products & versions

CVSS breakdown

Am I affected?

Remediation

References