{"id":"CVE-2001-0183","aliases":["EUVD-2001-0183","GHSA-6wc5-6x3h-cm5p"],"status":"published","title":"ipfw and ip6fw in FreeBSD 4.2 and earlier allows remote attackers to bypass access restrictions...","description":"ipfw and ip6fw in FreeBSD 4.2 and earlier allows remote attackers to bypass access restrictions by setting the ECE flag in a TCP packet, which makes the packet appear to be part of an established connection.","severity":{"version":"2.0","score":7.5,"vector":"AV:N/AC:L/Au:N/C:P/I:P/A:P","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-07","score":0.08094,"percentile":0.9485,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":true,"fix_available":false},"published":"2001-03-26T05:00:00Z","modified":"2026-06-16T21:53:49Z","exploits":[{"source":"exploitdb","id":"EDB-20593","title":"FreeBSD 3.x/4.x - 'ipfw' Filtering Evasion","type":"remote","platform":"freebsd","date":"2001-01-23","verified":true,"url":"https://www.exploit-db.com/exploits/20593"}],"products":[{"vendor":"freebsd","product":"freebsd"}],"references":[{"url":"http://www.securityfocus.com/bid/2293","tags":["vdb-entry","x_refsource_BID","x_transferred","Exploit","Patch","Vendor Advisory"]},{"url":"http://www.ciac.org/ciac/bulletins/l-029.shtml","tags":["third-party-advisory","government-resource","x_refsource_CIAC","x_transferred"]},{"url":"http://www.security-express.com/archives/bugtraq/2001-01/0424.html","tags":["mailing-list","x_refsource_BUGTRAQ","x_transferred"]},{"url":"https://exchange.xforce.ibmcloud.com/vulnerabilities/5998","tags":["vdb-entry","x_refsource_XF","x_transferred"]},{"url":"ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-01:08.ipfw.asc","tags":["vendor-advisory","x_refsource_FREEBSD","x_transferred","Patch","Vendor Advisory"]},{"url":"http://www.osvdb.org/1743","tags":["vdb-entry","x_refsource_OSVDB","x_transferred"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2001-0183"},{"url":"https://github.com/advisories/GHSA-6wc5-6x3h-cm5p"}],"sources":{"cve":[{"id":"CVE-2001-0183","description":"ipfw and ip6fw in FreeBSD 4.2 and earlier allows remote attackers to bypass access restrictions by setting the ECE flag in a TCP packet, which makes the packet appear to be part of an established connection.","status":"published","published":"2001-05-07T04:00:00Z","modified":"2024-08-08T04:14:06.663Z","updated_at":"2026-11-02T14:34:43.032065Z"}],"euvd":[{"id":"EUVD-2001-0183","description":"ipfw and ip6fw in FreeBSD 4.2 and earlier allows remote attackers to bypass access restrictions by setting the ECE flag in a TCP packet, which makes the packet appear to be part of an established connection.","status":"published","published":"2001-05-07T04:00:00Z","modified":"2024-08-08T04:14:06Z","updated_at":"2026-11-03T01:14:52.987378Z"}],"ghsa":[{"id":"GHSA-6wc5-6x3h-cm5p","title":"ipfw and ip6fw in FreeBSD 4.2 and earlier allows remote attackers to bypass access restrictions...","description":"ipfw and ip6fw in FreeBSD 4.2 and earlier allows remote attackers to bypass access restrictions by setting the ECE flag in a TCP packet, which makes the packet appear to be part of an established connection.","status":"published","published":"2022-05-03T03:07:07Z","modified":"2023-02-01T05:00:59Z","updated_at":"2026-11-02T14:49:38.712812Z"}],"nvd":[{"id":"CVE-2001-0183","description":"ipfw and ip6fw in FreeBSD 4.2 and earlier allows remote attackers to bypass access restrictions by setting the ECE flag in a TCP packet, which makes the packet appear to be part of an established connection.","status":"published","published":"2001-03-26T05:00:00Z","modified":"2026-06-16T21:53:49.973Z","cvss":[{"version":"2.0","score":7.5,"vector":"AV:N/AC:L/Au:N/C:P/I:P/A:P","level":"high","assessor":"primary"}],"updated_at":"2026-11-02T14:00:39.593487Z"}]}}