{"id":"CVE-2023-33010","kind":"vulnerability","aliases":["CVE-2023-33010"],"related":[],"title":"A buffer overflow vulnerability in the ID processing function in Zyxel ATP series firmware versions 4.32 through…","description":"A buffer overflow vulnerability in the ID processing function in Zyxel ATP series firmware versions 4.32 through 5.36 Patch 1, USG FLEX series firmware versions 4.50 through 5.36 Patch 1, USG FLEX 50(W) firmware versions 4.25 through 5.36 Patch 1, USG20(W)-VPN firmware versions 4.25 through 5.36 Patch 1, VPN series firmware versions 4.30 through 5.36 Patch 1, ZyWALL/USG series firmware versions 4.25 through 4.73 Patch 1, could allow an unauthenticated attacker to cause denial-of-service (DoS) conditions and even a remote code execution on an affected device.","summary":"Zyxel ATP, USG FLEX, USG20(W)-VPN, VPN and ZyWALL/USG firewalls have a buffer overflow in their ID processing function. An unauthenticated remote attacker can crash the device or run code on it.","severity":"critical","cvss":9.8,"epss":null,"exploited":true,"exploited_at":"2023-06-05T00:00:00+00:00","products":[{"name":"Zyxel Multiple Firewalls","fixed":[],"affected":"","ecosystem":"vendor"},{"name":"zyxel atp100 firmware","fixed":["5.36"],"affected":">= 4.32, < 5.36","ecosystem":"vendor"},{"name":"zyxel atp100 firmware","fixed":[],"affected":"= 5.36","ecosystem":"vendor"},{"name":"zyxel atp200 firmware","fixed":["5.36"],"affected":">= 4.32, < 5.36","ecosystem":"vendor"},{"name":"zyxel atp200 firmware","fixed":[],"affected":"= 5.36","ecosystem":"vendor"},{"name":"zyxel atp500 firmware","fixed":["5.36"],"affected":">= 4.32, < 5.36","ecosystem":"vendor"},{"name":"zyxel atp500 firmware","fixed":[],"affected":"= 5.36","ecosystem":"vendor"},{"name":"zyxel atp100w firmware","fixed":["5.36"],"affected":">= 4.32, < 5.36","ecosystem":"vendor"},{"name":"zyxel atp100w firmware","fixed":[],"affected":"= 5.36","ecosystem":"vendor"},{"name":"zyxel atp700 firmware","fixed":["5.36"],"affected":">= 4.32, < 5.36","ecosystem":"vendor"},{"name":"zyxel atp700 firmware","fixed":[],"affected":"= 5.36","ecosystem":"vendor"},{"name":"zyxel atp800 firmware","fixed":["5.36"],"affected":">= 4.32, < 5.36","ecosystem":"vendor"},{"name":"zyxel atp800 firmware","fixed":[],"affected":"= 5.36","ecosystem":"vendor"},{"name":"zyxel usg flex 100 firmware","fixed":["5.36"],"affected":">= 4.50, < 5.36","ecosystem":"vendor"},{"name":"zyxel usg flex 100 firmware","fixed":[],"affected":"= 5.36","ecosystem":"vendor"},{"name":"zyxel usg flex 50 firmware","fixed":[],"affected":"= 5.36","ecosystem":"vendor"},{"name":"zyxel usg flex 200 firmware","fixed":["5.36"],"affected":">= 4.50, < 5.36","ecosystem":"vendor"},{"name":"zyxel usg flex 200 firmware","fixed":[],"affected":"= 5.36","ecosystem":"vendor"},{"name":"zyxel usg flex 500 firmware","fixed":["5.36"],"affected":">= 4.50, < 5.36","ecosystem":"vendor"},{"name":"zyxel usg flex 500 firmware","fixed":[],"affected":"= 5.36","ecosystem":"vendor"},{"name":"zyxel usg flex 700 firmware","fixed":["5.36"],"affected":">= 4.50, < 5.36","ecosystem":"vendor"},{"name":"zyxel usg flex 700 firmware","fixed":[],"affected":"= 5.36","ecosystem":"vendor"},{"name":"zyxel usg flex 100w firmware","fixed":[],"affected":"= 5.36","ecosystem":"vendor"},{"name":"zyxel usg flex 50w firmware","fixed":["5.36"],"affected":">= 4.25, < 5.36","ecosystem":"vendor"},{"name":"zyxel usg flex 50w firmware","fixed":[],"affected":"= 5.36","ecosystem":"vendor"},{"name":"zyxel usg 20w-vpn firmware","fixed":[],"affected":"= 5.36","ecosystem":"vendor"},{"name":"zyxel vpn100 firmware","fixed":["5.36"],"affected":">= 4.30, < 5.36","ecosystem":"vendor"},{"name":"zyxel vpn100 firmware","fixed":[],"affected":"= 5.36","ecosystem":"vendor"},{"name":"zyxel vpn50 firmware","fixed":["5.36"],"affected":">= 4.30, < 5.36","ecosystem":"vendor"},{"name":"zyxel vpn50 firmware","fixed":[],"affected":"= 5.36","ecosystem":"vendor"},{"name":"zyxel vpn300 firmware","fixed":["5.36"],"affected":">= 4.30, < 5.36","ecosystem":"vendor"},{"name":"zyxel vpn300 firmware","fixed":[],"affected":"= 5.36","ecosystem":"vendor"},{"name":"zyxel vpn1000 firmware","fixed":["5.36"],"affected":">= 4.30, < 5.36","ecosystem":"vendor"},{"name":"zyxel vpn1000 firmware","fixed":[],"affected":"= 5.36","ecosystem":"vendor"},{"name":"zyxel usg20-vpn firmware","fixed":["5.36"],"affected":">= 4.30, < 5.36","ecosystem":"vendor"},{"name":"zyxel usg20-vpn firmware","fixed":[],"affected":"= 5.36","ecosystem":"vendor"},{"name":"zyxel usg 40 firmware","fixed":["4.73"],"affected":">= 4.25, < 4.73","ecosystem":"vendor"},{"name":"zyxel usg 40 firmware","fixed":[],"affected":"= 4.73","ecosystem":"vendor"},{"name":"zyxel usg 40w firmware","fixed":["4.73"],"affected":">= 4.25, < 4.73","ecosystem":"vendor"},{"name":"zyxel usg 40w firmware","fixed":[],"affected":"= 4.73","ecosystem":"vendor"},{"name":"zyxel usg 60w firmware","fixed":["4.73"],"affected":">= 4.25, < 4.73","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["exploited","firewall","infrastructure","self-hosted","zyxel"],"not_affected_if":["no-zyxel-firewall"],"how_to_check":"Identify Zyxel firewall models and firmware versions in use; compare against the vendor advisory for affected versions.","fix":"Apply the vendor firmware update per Zyxel's advisory (CISA KEV required action: apply updates per vendor instructions).","status":"open","published_at":"2023-05-24T13:15:09+00:00","first_seen_at":"2026-10-23T19:11:51+00:00","triaged_at":"2026-10-23T21:06:41+00:00","updated_at":"2026-10-23T22:29:04+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-23T21:06:41Z","model":"claude-haiku-5-5","output":{"fix":"Apply the vendor firmware update per Zyxel's advisory (CISA KEV required action: apply updates per vendor instructions).\nunknown","reach":"internet","impact":"high","summary":"Zyxel ATP, USG FLEX, USG20(W)-VPN, VPN and ZyWALL/USG firewalls have a buffer overflow in their ID processing function. An unauthenticated remote attacker can crash the device or run code on it.","category":"infrastructure","who_cares":["zyxel","firewall","self-hosted"],"confidence":0.6,"needs_auth":"no","worst_case":"Unauthenticated attacker runs code on the firewall or crashes it","analyst_note":"Find the Zyxel advisory for CVE-2023-33010 to get affected and fixed firmware versions and any required settings.","how_to_check":"Identify Zyxel firewall models and firmware versions in use; compare against the vendor advisory for affected versions.\nunknown","needs_analyst":true,"not_affected_if":["no-zyxel-firewall"],"user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000489,"input_tokens":2876,"output_tokens":402,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2023':18A,21A '-33010':19A,22A '1':239C,249C,260C,270C,279C,288C '100':65A,70A '100w':110A '200':80A,85A '20w':125A '20w-vpn':124A '4.25':256C,266C,284C '4.30':275C '4.32':16A,235C '4.50':245C '4.73':286C '40':164A,168A '40w':172A,176A '5.36':237C,247C,258C,268C,277C '50':75A,252C '500':90A,95A '50w':115A,120A '60w':180A '700':100A,105A 'affect':310C 'allow':290C 'atp':12A,190B,231C 'atp100':27A,30A 'atp100w':45A,48A 'atp200':33A,36A 'atp500':39A,42A 'atp700':51A,54A 'atp800':57A,60A 'attack':212B,293C 'buffer':2A,202B,221C 'caus':295C 'code':219B,306C 'condit':301C 'could':289C 'crash':214B 'cve':17A,20A 'denial':297C 'denial-of-servic':296C 'devic':216B,311C 'dos':300C 'even':303C 'execut':307C 'exploit':182B 'firewal':183B,199B 'firewalls':25A 'firmwar':14A,233C,243C,254C,264C,273C,282C 'firmware':28A,31A,34A,37A,40A,43A,46A,49A,52A,55A,58A,61A,66A,71A,76A,81A,86A,91A,96A,101A,106A,111A,116A,121A,127A,130A,133A,136A,139A,142A,145A,148A,151A,156A,161A,165A,169A,173A,177A,181A 'flex':64A,69A,74A,79A,84A,89A,94A,99A,104A,109A,114A,119A,192B,241C,251C 'function':9A,208B,228C 'host':187B 'id':7A,206B,226C 'infrastructur':184B 'multiple':24A 'overflow':3A,203B,222C 'patch':238C,248C,259C,269C,278C,287C 'process':8A,207B,227C 'remot':211B,305C 'run':218B 'self':186B 'self-host':185B 'seri':13A,232C,242C,272C,281C 'servic':299C 'unauthent':210B,292C 'usg':63A,68A,73A,78A,83A,88A,93A,98A,103A,108A,113A,118A,123A,163A,167A,171A,175A,179A,191B,240C,250C 'usg20':154A,159A,193B,261C 'usg20-vpn':153A,158A 'version':15A,234C,244C,255C,265C,274C,283C 'vpn':126A,155A,160A,195B,196B,263C,271C 'vpn100':129A,132A 'vpn1000':147A,150A 'vpn300':141A,144A 'vpn50':135A,138A 'vulner':4A,223C 'w':194B,253C,262C 'zywall/usg':198B,280C 'zyxel':11A,23A,26A,29A,32A,35A,38A,41A,44A,47A,50A,53A,56A,59A,62A,67A,72A,77A,82A,87A,92A,97A,102A,107A,112A,117A,122A,128A,131A,134A,137A,140A,143A,146A,149A,152A,157A,162A,166A,170A,174A,178A,188B,189B,230C","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2023-05-24T13:15:09+00:00","kev":{"dateAdded":"2023-06-05","dueDate":"2023-06-26","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":"security@zyxel.com.tw","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2023-33010","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2023-33010","severity":null,"published_at":"2023-06-05T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:51+00:00","fetched_at":"2026-10-25T11:39:15+00:00","note":null},{"source":"nvd","external_id":"CVE-2023-33010","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-33010","severity":null,"published_at":"2023-05-24T13:15:09+00:00","modified_at":"2026-06-17T06:00:17+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"}