{"id":"CVE-2016-0034","kind":"vulnerability","aliases":["CVE-2016-0034"],"related":[],"title":"Microsoft Silverlight 5 before 5.1.41212.0 mishandles negative offsets during decoding, which allows remote…","description":"Microsoft Silverlight 5 before 5.1.41212.0 mishandles negative offsets during decoding, which allows remote attackers to execute arbitrary code or cause a denial of service (object-header corruption) via a crafted web site, aka \"Silverlight Runtime Remote Code Execution Vulnerability.\"","summary":"Microsoft Silverlight's runtime mishandles negative offsets during decoding, letting a crafted input cause remote code execution or a denial of service. CISA lists it as actively exploited, and the sources note ransomware use.","severity":"critical","cvss":9.3,"epss":0.69397,"exploited":true,"exploited_at":"2022-05-25T00:00:00+00:00","products":[{"name":"microsoft silverlight","fixed":["5.1.41212.0"],"affected":">= 5.0, < 5.1.41212.0","ecosystem":"vendor"},{"name":"Microsoft Silverlight","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["browsers","exploited","ransomware","runtime","silverlight","windows"],"not_affected_if":["no-silverlight-installed"],"how_to_check":"Check whether Silverlight is installed on Windows machines (Add or remove programs, or the Silverlight Configuration app); unknown for a specific command.","fix":"Remove Silverlight, since the product is end-of-life and no longer receives fixes (per CISA: disconnect if still in use).","status":"open","published_at":"2016-01-13T05:59:22+00:00","first_seen_at":"2026-10-23T19:11:52+00:00","triaged_at":"2026-10-23T21:13:06+00:00","updated_at":"2026-10-24T00:09:51+00:00","category":"runtime","confidence":0.6,"triage":{"at":"2026-10-23T21:13:06Z","model":"claude-haiku-5-5","output":{"fix":"Remove Silverlight, since the product is end-of-life and no longer receives fixes (per CISA: disconnect if still in use).","reach":"internet","impact":"high","summary":"Microsoft Silverlight's runtime mishandles negative offsets during decoding, letting a crafted input cause remote code execution or a denial of service. CISA lists it as actively exploited, and the sources note ransomware use.","category":"runtime","who_cares":["windows","silverlight","browsers"],"confidence":0.6,"needs_auth":"no","worst_case":"Attacker runs code remotely on the affected machine.","analyst_note":"Confirm affected Silverlight versions and the exact trigger (web content vs. local) from the Microsoft bulletin MS16-006 or the NVD entry for CVE-2016-0034.","how_to_check":"Check whether Silverlight is installed on Windows machines (Add or remove programs, or the Silverlight Configuration app); unknown for a specific command.","needs_analyst":true,"not_affected_if":["no-silverlight-installed"],"user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000488,"input_tokens":2854,"output_tokens":405,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-0034':16A,19A '-2016':15A,18A '5':3A,66C '5.1.41212.0':5A,68C 'activ':56B 'aka':97C 'allow':12A,75C 'arbitrari':80C 'attack':77C 'browser':24B 'caus':43B,83C 'cisa':52B 'code':45B,81C,101C 'corrupt':91C 'craft':41B,94C 'cve':14A,17A 'decod':10A,38B,73C 'denial':49B,85C 'execut':46B,79C,102C 'exploit':25B,57B 'header':90C 'input':42B 'let':39B 'list':53B 'microsoft':1A,20A,22A,30B,64C 'mishandl':6A,34B,69C 'negat':7A,35B,70C 'note':61B 'object':89C 'object-head':88C 'offset':8A,36B,71C 'ransomwar':26B,62B 'remot':13A,44B,76C,100C 'runtim':27B,33B,99C 'servic':51B,87C 'silverlight':2A,21A,23A,28B,31B,65C,98C 'site':96C 'sourc':60B 'use':63B 'via':92C 'vulner':103C 'web':95C 'window':29B","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2016-01-13T05:59:22+00:00","kev":{"dateAdded":"2022-05-25","dueDate":"2022-06-15","requiredAction":"The impacted products are end-of-life and should be disconnected if still in use.","knownRansomwareCampaignUse":"Known"},"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","cvss_by":"nvd@nist.gov","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2016-0034","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2016-0034","severity":null,"published_at":"2022-05-25T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:52+00:00","fetched_at":"2026-10-25T13:39:31+00:00","note":null},{"source":"epss","external_id":"CVE-2016-0034","url":"https://api.first.org/data/v1/epss?cve=CVE-2016-0034","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-23T19:13:45+00:00","fetched_at":"2026-10-23T19:13:45+00:00","note":null},{"source":"nvd","external_id":"CVE-2016-0034","url":"https://nvd.nist.gov/vuln/detail/CVE-2016-0034","severity":null,"published_at":"2016-01-13T05:59:22+00:00","modified_at":"2026-08-14T05:16:53+00:00","first_seen_at":"2026-10-23T22:29:04+00:00","fetched_at":"2026-10-23T22:29:04+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"}