CVE-2017-11357 — Telerik Ui For Asp.Net Ajax
CRITICALCVE-2017-11357 is a critical-severity (CVSS 9.8) Unrestricted File Upload vulnerability in progress telerik ui for asp.net ajax. It is in CISA's Known Exploited Vulnerabilities catalog (added 2023-01-26) and has been used in ransomware campaigns — treat it as actively exploited and patch now. A fix is available — see the affected versions and patch details below.
Progress Telerik UI for ASP.NET AJAX before R2 2017 SP2 does not properly restrict user input to RadAsyncUpload, which allows remote attackers to perform arbitrary file uploads or execute…
Exploitation Status
Actively exploited in the wild
- Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2023-01-26 — including use in ransomware campaigns. Federal agencies were required to remediate by 2023-02-16.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2017-11357.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2017-11357 by exploitation likelihood (EPSS) against impact (CVSS). In the shaded patch-first corner (EPSS 50%+, CVSS 7.0+).
Where this sits among everything scored
Of 394,803 CVEs with a current EPSS score, this one falls in the 50–90% band (highlighted). Counts from FIRST.org, log-scaled.
Description
Progress Telerik UI for ASP.NET AJAX before R2 2017 SP2 does not properly restrict user input to RadAsyncUpload, which allows remote attackers to perform arbitrary file uploads or execute arbitrary code.
Affected Products
telerik ui for asp.net ajaxprogressResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Telerik UI for ASP.NET AJAX 2012.3.1308 < 2017.1.118 - Arbitrary File Upload
by Paul Taylor · Jan 24, 2018
Detection & mitigation playbook
Vendor / applianceDetect
Inventory every progress telerik ui for asp.net ajax deployment and check each version against the affected-products list above.
Fix
Apply the progress telerik ui for asp.net ajax security patch or hotfix for CVE-2017-11357 on the affected version, following the vendor advisory for your exact build.
Workarounds
Treat uploaded files as untrusted until proven otherwise: validate the actual content type rather than the supplied extension, store uploads outside the web root on a volume mounted without execute permission, and rename them to server-generated identifiers so an attacker cannot choose the path a request will later resolve. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.
Frequently Asked Questions
Is CVE-2017-11357 being exploited in your environment?
Detect and block the exploit chain at execution, on systems you cannot patch yet.