{"id":"CVE-2017-9248","kind":"vulnerability","aliases":["CVE-2017-9248"],"related":[],"title":"Progress ASP.NET AJAX and Sitefinity: Progress Telerik UI for ASP.NET AJAX and Sitefinity Cryptographic Weakness Vulnerability","description":"Progress Telerik UI for ASP.NET AJAX and Sitefinity have a cryptographic weakness in Telerik.Web.UI.dll that can be exploited to disclose encryption keys (Telerik.Web.UI.DialogParametersEncryptionKey and/or the MachineKey), perform cross-site-scripting (XSS) attacks, compromise the ASP.NET ViewState, and/or upload and download files.\n\nCISA required action: Apply updates per vendor instructions.","summary":"Progress Telerik UI for ASP.NET AJAX and Sitefinity contain a cryptographic weakness in Telerik.Web.UI.dll. An attacker can use it to recover encryption keys, run cross-site scripting, tamper with ViewState, and upload or download files.","severity":"critical","cvss":9.8,"epss":0.75098,"exploited":true,"exploited_at":"2021-11-03T00:00:00+00:00","products":[{"name":"Progress ASP.NET AJAX and Sitefinity","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["asp.net","exploited","iis","package","sitefinity","telerik","windows"],"not_affected_if":["no-sitefinity","no-telerik-ui"],"how_to_check":"Search deployed web application bins for Telerik.Web.UI.dll and check its version against the vendor advisory; the sources do not give affected version ranges.","fix":"Apply the vendor update per Progress guidance; the sources do not name a fixed version.\nRotate Telerik.Web.UI.DialogParametersEncryptionKey and the MachineKey after patching.","status":"open","published_at":"2017-07-03T19:29:00+00:00","first_seen_at":"2026-10-23T19:11:53+00:00","triaged_at":"2026-10-23T20:29:35+00:00","updated_at":"2026-10-23T20:29:35+00:00","category":"package","confidence":0.75,"triage":{"at":"2026-10-23T20:29:35Z","model":"claude-haiku-5-5","output":{"fix":"Apply the vendor update per Progress guidance; the sources do not name a fixed version.\nRotate Telerik.Web.UI.DialogParametersEncryptionKey and the MachineKey after patching.","summary":"Progress Telerik UI for ASP.NET AJAX and Sitefinity contain a cryptographic weakness in Telerik.Web.UI.dll. An attacker can use it to recover encryption keys, run cross-site scripting, tamper with ViewState, and upload or download files.","category":"package","who_cares":["asp.net","telerik","sitefinity","windows","iis"],"confidence":0.75,"analyst_note":"Sources do not list affected or fixed versions; pull the Progress advisory and confirm version ranges and the fixed build for Telerik UI and Sitefinity.","how_to_check":"Search deployed web application bins for Telerik.Web.UI.dll and check its version against the vendor advisory; the sources do not give affected version ranges.\nunknown","needs_analyst":true,"not_affected_if":["no-telerik-ui","no-sitefinity"],"severity_if_unknown":"critical"},"cost_usd":0.00042,"input_tokens":2235,"output_tokens":392,"severity_before":"critical"},"analyst_status":null,"analyst_note":null,"search":"'-2017':18A,21A '-9248':19A,22A 'action':115C 'ajax':3A,11A,25A,40B,76C 'and':26A 'and/or':94C,108C 'appli':116C 'asp.net':2A,10A,24A,28B,39B,75C,106C 'attack':50B,103C 'cisa':113C 'compromis':104C 'contain':43B 'cross':60B,99C 'cross-sit':59B 'cross-site-script':98C 'cryptograph':14A,45B,81C 'cve':17A,20A 'disclos':90C 'download':69B,111C 'encrypt':56B,91C 'exploit':29B,88C 'file':70B,112C 'ii':30B 'instruct':120C 'key':57B,92C 'machinekey':96C 'packag':31B 'per':118C 'perform':97C 'progress':1A,6A,23A,35B,71C 'recov':55B 'requir':114C 'run':58B 'script':62B,101C 'site':61B,100C 'sitefin':5A,13A,32B,42B,78C 'sitefinity':27A 'tamper':63B 'telerik':7A,33B,36B,72C 'telerik.web.ui.dialogparametersencryptionkey':93C 'telerik.web.ui.dll':48B,84C 'ui':8A,37B,73C 'updat':117C 'upload':67B,109C 'use':52B 'vendor':119C 'viewstat':65B,107C 'vulner':16A 'weak':15A,46B,82C 'window':34B 'xss':102C","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2017-07-03T19:29:00+00:00","kev":{"dateAdded":"2021-11-03","dueDate":"2022-05-03","requiredAction":"Apply updates per vendor instructions.","knownRansomwareCampaignUse":"Unknown"},"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvss_by":"nvd@nist.gov","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2017-9248","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2017-9248","severity":null,"published_at":"2021-11-03T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:53+00:00","fetched_at":"2026-10-25T16:39:50+00:00","note":null},{"source":"epss","external_id":"CVE-2017-9248","url":"https://api.first.org/data/v1/epss?cve=CVE-2017-9248","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-23T19:13:44+00:00","fetched_at":"2026-10-23T19:13:44+00:00","note":null},{"source":"nvd","external_id":"CVE-2017-9248","url":"https://nvd.nist.gov/vuln/detail/CVE-2017-9248","severity":null,"published_at":"2017-07-03T19:29:00+00:00","modified_at":"2026-06-17T01:27:44+00:00","first_seen_at":"2026-10-23T19:35:23+00:00","fetched_at":"2026-10-23T19:35:23+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}