{"id":"CVE-2025-20393","kind":"vulnerability","aliases":["CVE-2025-20393"],"related":[],"title":"A vulnerability in the Spam Quarantine feature of Cisco AsyncOS Software for Cisco Secure Email Gateway and Cisco…","description":"A vulnerability in the Spam Quarantine feature of Cisco AsyncOS Software for Cisco Secure Email Gateway and Cisco Secure Email and Web Manager could allow an unauthenticated, remote attacker to execute arbitrary system commands on an affected device with root privileges.\r\n\r\nThis vulnerability is due to insufficient validation of HTTP requests by the Spam Quarantine feature. An attacker could exploit this vulnerability by sending a crafted HTTP request to the affected device. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system with&nbsp;root privileges.","summary":"Cisco Secure Email Gateway, Secure Email, AsyncOS and Web Manager appliances have an input validation flaw that lets an attacker run arbitrary commands. The commands run as root on the underlying appliance OS, and CISA lists it as actively exploited.","severity":"critical","cvss":10.0,"epss":null,"exploited":true,"exploited_at":"2025-12-17T00:00:00+00:00","products":[{"name":"Cisco Multiple Products","fixed":[],"affected":"","ecosystem":"vendor"},{"name":"cisco asyncos","fixed":["15.0.5-016"],"affected":"< 15.0.5-016","ecosystem":"vendor"},{"name":"cisco asyncos","fixed":["15.5.4-012"],"affected":">= 15.5, < 15.5.4-012","ecosystem":"vendor"},{"name":"cisco asyncos","fixed":["16.0.4-016"],"affected":">= 16.0, < 16.0.4-016","ecosystem":"vendor"},{"name":"cisco asyncos","fixed":["15.0.2-007"],"affected":"< 15.0.2-007","ecosystem":"vendor"},{"name":"cisco asyncos","fixed":["15.5.4-007"],"affected":">= 15.5, < 15.5.4-007","ecosystem":"vendor"},{"name":"cisco asyncos","fixed":["16.0.4-010"],"affected":">= 16.0, < 16.0.4-010","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["cisco","email-security-appliance","exploited","infrastructure","secure-email-gateway","self-hosted"],"not_affected_if":["cloud-hosted-only"],"how_to_check":null,"fix":"Apply the mitigations in Cisco's vendor advisory; if none are available, CISA says to discontinue use of the product. Affected and fixed versions: unknown from these sources.","status":"open","published_at":"2025-12-17T00:00:00+00:00","first_seen_at":"2026-10-23T19:11:51+00:00","triaged_at":"2026-10-23T20:42:42+00:00","updated_at":"2026-10-23T23:44:51+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-23T20:42:42Z","model":"claude-haiku-5-5","output":{"fix":"Apply the mitigations in Cisco's vendor advisory; if none are available, CISA says to discontinue use of the product. Affected and fixed versions: unknown from these sources.","reach":"unknown","summary":"Cisco Secure Email Gateway, Secure Email, AsyncOS and Web Manager appliances have an input validation flaw that lets an attacker run arbitrary commands. The commands run as root on the underlying appliance OS, and CISA lists it as actively exploited.","category":"infrastructure","who_cares":["cisco","secure-email-gateway","email-security-appliance","self-hosted"],"confidence":0.6,"needs_auth":"unknown","worst_case":"Attacker runs arbitrary commands as root on the appliance","analyst_note":"Find Cisco's advisory for CVE-2025-20393 to get affected versions, fixed releases, how to check exposure and whether the flaw is network-reachable without credentials.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["cloud-hosted-only"],"user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"critical"},"cost_usd":0.000459,"input_tokens":2572,"output_tokens":403,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2025':20A,23A '-20393':21A,24A 'activ':92B 'affect':130C,164C 'allow':118C,170C 'applianc':44B,64B,85B 'arbitrari':75B,125C,175C 'asynco':10A,60B,103C 'asyncos':29A,31A,33A,35A,37A,39A 'attack':73B,122C,151C,172C 'cisa':88B 'cisco':9A,13A,18A,25A,28A,30A,32A,34A,36A,38A,40B,54B,102C,106C,111C 'command':76B,78B,127C,176C 'could':117C,152C,169C 'craft':159C 'cve':19A,22A 'devic':131C,165C 'due':138C 'email':15A,42B,49B,56B,59B,108C,113C 'email-security-appli':41B 'execut':124C,174C 'exploit':45B,93B,153C,168C 'featur':7A,100C,149C 'flaw':69B 'gateway':16A,50B,57B,109C 'host':53B 'http':143C,160C 'infrastructur':46B 'input':67B 'insuffici':140C 'let':71B 'list':89B 'manag':63B,116C 'multiple':26A 'oper':180C 'os':86B 'privileg':134C,184C 'products':27A 'quarantin':6A,99C,148C 'remot':121C 'request':144C,161C 'root':81B,133C,183C 'run':74B,79B 'secur':14A,43B,48B,55B,58B,107C,112C 'secure-email-gateway':47B 'self':52B 'self-host':51B 'send':157C 'softwar':11A,104C 'spam':5A,98C,147C 'success':167C 'system':126C,181C 'unauthent':120C 'under':84B,179C 'valid':68B,141C 'vulner':2A,95C,136C,155C 'web':62B,115C","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2025-12-17T00:00:00+00:00","kev":{"dateAdded":"2025-12-17","dueDate":"2025-12-24","requiredAction":"Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.","knownRansomwareCampaignUse":"Unknown"},"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","cvss_by":"psirt@cisco.com","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2025-20393","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2025-20393","severity":null,"published_at":"2025-12-17T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:51+00:00","fetched_at":"2026-10-25T13:39:29+00:00","note":null},{"source":"nvd","external_id":"CVE-2025-20393","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-20393","severity":null,"published_at":"2025-12-17T17:15:48+00:00","modified_at":"2026-06-17T08:41:39+00:00","first_seen_at":"2026-10-23T23:44:51+00:00","fetched_at":"2026-10-23T23:44:51+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"}