{"id":"CVE-2021-35394","kind":"vulnerability","aliases":["CVE-2021-35394"],"related":[],"title":"Realtek Jungle Software Development Kit (SDK): Realtek Jungle SDK Remote Code Execution Vulnerability","description":"Realtek Jungle SDK version v2.x up to v3.4.14B provides a diagnostic tool called 'MP Daemon' that is usually compiled as 'UDPServer' binary. The binary is affected by multiple memory corruption vulnerabilities and an arbitrary command injection vulnerability that can be exploited by remote unauthenticated attackers.","summary":"Realtek Jungle SDK, firmware used in network devices such as routers and switches, contains memory corruption bugs that allow remote code execution. An attacker who reaches the device over the network can run code on it, which typically means full control of the device.","severity":"critical","cvss":10.0,"epss":0.99877,"exploited":true,"exploited_at":"2021-12-10T00:00:00+00:00","products":[{"name":"Realtek Jungle Software Development Kit (SDK)","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["embedded-devices","exploited","infrastructure","realtek","routers","self-hosted"],"not_affected_if":["managed-hosting","no-realtek-jungle-sdk"],"how_to_check":null,"fix":"Apply updates per vendor instructions, as CISA directs; the sources do not name a fixed version.","status":"open","published_at":"2021-08-16T12:15:07+00:00","first_seen_at":"2026-10-23T19:11:53+00:00","triaged_at":"2026-10-23T21:31:54+00:00","updated_at":"2026-10-23T21:57:35+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-23T21:31:54Z","model":"claude-haiku-5-5","output":{"fix":"Apply updates per vendor instructions, as CISA directs; the sources do not name a fixed version.","reach":"network","impact":"high","summary":"Realtek Jungle SDK, firmware used in network devices such as routers and switches, contains memory corruption bugs that allow remote code execution. An attacker who reaches the device over the network can run code on it, which typically means full control of the device.","category":"infrastructure","who_cares":["realtek","routers","embedded-devices","self-hosted"],"confidence":0.6,"needs_auth":"unknown","worst_case":"Attacker runs code on the device and takes full control of it.","analyst_note":"Find the affected Realtek device models and vendor firmware advisory; the sources list no fixed version or check method (see CISA KEV entry for CVE-2021-35394).","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["no-realtek-jungle-sdk","managed-hosting"],"user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"critical"},"cost_usd":0.000468,"input_tokens":2849,"output_tokens":367,"severity_before":"unknown"},"analyst_status":"queued","analyst_note":"Find the affected Realtek device models and vendor firmware advisory; the sources list no fixed version or check method (see CISA KEV entry for CVE-2021-35394).","search":"'-2021':15A,18A '-35394':16A,19A 'affect':105C 'allow':54B 'arbitrari':113C 'attack':59B,124C 'binari':101C,103C 'bug':52B 'call':92C 'code':11A,56B,69B 'command':114C 'compil':98C 'contain':49B 'control':76B 'corrupt':51B,109C 'cve':14A,17A 'daemon':94C 'develop':4A 'development':23A 'devic':28B,43B,63B,79B 'diagnost':90C 'embed':27B 'embedded-devic':26B 'execut':12A,57B 'exploit':29B,120C 'firmwar':39B 'full':75B 'host':35B 'infrastructur':30B 'inject':115C 'jungl':2A,8A,37B,81C 'jungle':21A 'kit':5A,24A 'mean':74B 'memori':50B,108C 'mp':93C 'multipl':107C 'network':42B,66B 'provid':88C 'reach':61B 'realtek':1A,7A,20A,31B,36B,80C 'remot':10A,55B,122C 'router':32B,46B 'run':68B 'sdk':6A,9A,25A,38B,82C 'self':34B 'self-host':33B 'softwar':3A 'software':22A 'switch':48B 'tool':91C 'typic':73B 'udpserv':100C 'unauthent':123C 'use':40B 'usual':97C 'v2.x':84C 'v3.4.14b':87C 'version':83C 'vulner':13A,110C,116C","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2021-08-16T12:15:07+00:00","kev":{"dateAdded":"2021-12-10","dueDate":"2021-12-24","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-2021-35394","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2021-35394","severity":null,"published_at":"2021-12-10T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:53+00:00","fetched_at":"2026-10-25T10:39:07+00:00","note":null},{"source":"epss","external_id":"CVE-2021-35394","url":"https://api.first.org/data/v1/epss?cve=CVE-2021-35394","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-2021-35394","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-35394","severity":null,"published_at":"2021-08-16T12:15:07+00:00","modified_at":"2026-06-17T03:57:29+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"}