{"id":"CVE-2021-38000","kind":"vulnerability","aliases":["CVE-2021-38000"],"related":[],"title":"Google Chromium Intents: Google Chromium Intents Improper Input Validation Vulnerability","description":"Google Chromium Intents contains an improper input validation vulnerability that allows a remote attacker to arbitrarily browser to a malicious URL via a crafted HTML page. This vulnerability could affect multiple web browsers that utilize Chromium, including, but not limited to, Google Chrome, Microsoft Edge, and Opera.\n\nCISA required action: Apply updates per vendor instructions.","summary":"An improper input validation flaw in Chromium's Intents handling lets a crafted HTML page make the browser navigate to an attacker-chosen URL. CISA lists it as actively exploited, and the same flaw affects Chromium-based browsers such as Chrome, Edge and Opera.","severity":"medium","cvss":6.1,"epss":0.04948,"exploited":true,"exploited_at":"2021-11-03T00:00:00+00:00","products":[{"name":"Google Chromium Intents","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["browser-users","chrome","chromium","edge","exploited","opera","vendor"],"not_affected_if":["fully-patched-browser"],"how_to_check":"Check the installed browser version (chrome://version, edge://version, or opera://about) and compare it with the fixed release in the vendor advisory.","fix":"Update Chrome, Edge, Opera and other Chromium-based browsers to the latest release per vendor instructions, as CISA requires.","status":"open","published_at":"2021-11-03T00:00:00+00:00","first_seen_at":"2026-10-23T19:11:53+00:00","triaged_at":"2026-10-23T21:39:32+00:00","updated_at":"2026-10-23T21:57:35+00:00","category":"vendor","confidence":0.6,"triage":{"at":"2026-10-23T21:39:32Z","model":"claude-haiku-5-5","output":{"fix":"Update Chrome, Edge, Opera and other Chromium-based browsers to the latest release per vendor instructions, as CISA requires.\nunknown","reach":"internet","impact":"medium","summary":"An improper input validation flaw in Chromium's Intents handling lets a crafted HTML page make the browser navigate to an attacker-chosen URL. CISA lists it as actively exploited, and the same flaw affects Chromium-based browsers such as Chrome, Edge and Opera.","category":"vendor","who_cares":["chromium","chrome","edge","opera","browser-users"],"confidence":0.6,"needs_auth":"no","worst_case":"Attacker redirects the victim's browser to a malicious URL via crafted page.","analyst_note":"Confirm affected and fixed Chromium versions from the Chrome releases blog or the NVD entry for CVE-2021-38000; sources give no version range.","how_to_check":"Check the installed browser version (chrome://version, edge://version, or opera://about) and compare it with the fixed release in the vendor advisory.\nunknown\nunknown","needs_analyst":true,"not_affected_if":["fully-patched-browser"],"user_interaction":"yes","needs_special_setup":"no","severity_if_unknown":"unknown"},"cost_usd":0.000511,"input_tokens":2892,"output_tokens":443,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2021':12A,15A '-38000':13A,16A 'action':124C 'activ':58B 'affect':64B,104C 'allow':85C 'appli':125C 'arbitrarili':90C 'attack':51B,88C 'attacker-chosen':50B 'base':67B 'browser':21B,46B,68B,91C,107C 'browser-us':20B 'chosen':52B 'chrome':23B,71B,117C 'chromium':2A,5A,18A,24B,35B,66B,76C,110C 'chromium-bas':65B 'cisa':54B,122C 'contain':78C 'could':103C 'craft':41B,98C 'cve':11A,14A 'edg':25B,72B,119C 'exploit':26B,59B 'flaw':33B,63B 'googl':1A,4A,75C,116C 'google':17A 'handl':38B 'html':42B,99C 'improp':7A,30B,80C 'includ':111C 'input':8A,31B,81C 'instruct':129C 'intent':3A,6A,37B,77C 'intents':19A 'let':39B 'limit':114C 'list':55B 'make':44B 'malici':94C 'microsoft':118C 'multipl':105C 'navig':47B 'opera':27B,74B,121C 'page':43B,100C 'per':127C 'remot':87C 'requir':123C 'updat':126C 'url':53B,95C 'user':22B 'util':109C 'valid':9A,32B,82C 'vendor':28B,128C 'via':96C 'vulner':10A,83C,102C 'web':106C","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2021-11-03T00:00:00+00:00","kev":{"dateAdded":"2021-11-03","dueDate":"2021-11-17","requiredAction":"Apply updates per vendor instructions.","knownRansomwareCampaignUse":"Unknown"},"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","cvss_by":"nvd@nist.gov","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2021-38000","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2021-38000","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":"2026-10-25T20:35:38+00:00","note":null},{"source":"epss","external_id":"CVE-2021-38000","url":"https://api.first.org/data/v1/epss?cve=CVE-2021-38000","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-2021-38000","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-38000","severity":null,"published_at":"2021-11-23T22:15:07+00:00","modified_at":"2026-06-17T04:01:23+00:00","first_seen_at":"2026-10-23T21:57:35+00:00","fetched_at":"2026-10-23T21:57:35+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"}