{"id":"CVE-2021-31800","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-31800","generatedAt":"2026-11-05T01:28:37.503Z","title":"Multiple path traversal vulnerabilities exist in smbserver.py in Impacket through 0.9.22.","description":"Multiple path traversal vulnerabilities exist in smbserver.py in Impacket through 0.9.22. An attacker that connects to a running smbserver instance can list and write to arbitrary files via ../ directory traversal. This could potentially be abused to achieve arbitrary code execution by replacing /etc/shadow or an SSH authorized key.","published":"2021-05-05T11:15:07.000Z","lastModified":"2026-06-17T03:52:15.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.1","score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-22"],"affected":["secureauth/impacket","fedoraproject/fedora"],"epss":{"score":0.19409,"percentile":0.97365,"date":"2026-11-03","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"urgent","text":"EPSS puts the probability of exploitation in the next 30 days at 19.4%, higher than 97% of all known CVEs. Patch or mitigate before the next change window."},"changes":[],"references":[{"url":"https://github.com/SecureAuthCorp/impacket/blob/cb6d43a677c338db930bc4e9161620832c1ec624/impacket/smbserver.py#L2008","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/SecureAuthCorp/impacket/blob/cb6d43a677c338db930bc4e9161620832c1ec624/impacket/smbserver.py#L2958","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/SecureAuthCorp/impacket/blob/cb6d43a677c338db930bc4e9161620832c1ec624/impacket/smbserver.py#L3485","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/SecureAuthCorp/impacket/blob/cb6d43a677c338db930bc4e9161620832c1ec624/impacket/smbserver.py#L876","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/SecureAuthCorp/impacket/commit/49c643bf66620646884ed141c94e5fdd85bcdd2f","tags":["Patch","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/SecureAuthCorp/impacket/releases","tags":["Release Notes","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IPXDPWCAPVX3UWYZ3N2T5OLBSBBUHJP6/","source":"cve@mitre.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KRV2C5DATXBHG6TF6CEEX54KZ75THQS3/","source":"cve@mitre.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UF56LYB27LHEIFJTFHU3M75NMNNK2SCG/","source":"cve@mitre.org"},{"url":"https://github.com/SecureAuthCorp/impacket/blob/cb6d43a677c338db930bc4e9161620832c1ec624/impacket/smbserver.py#L2008","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/SecureAuthCorp/impacket/blob/cb6d43a677c338db930bc4e9161620832c1ec624/impacket/smbserver.py#L2958","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/SecureAuthCorp/impacket/blob/cb6d43a677c338db930bc4e9161620832c1ec624/impacket/smbserver.py#L3485","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/SecureAuthCorp/impacket/blob/cb6d43a677c338db930bc4e9161620832c1ec624/impacket/smbserver.py#L876","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/SecureAuthCorp/impacket/commit/49c643bf66620646884ed141c94e5fdd85bcdd2f","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/SecureAuthCorp/impacket/releases","tags":["Release Notes","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IPXDPWCAPVX3UWYZ3N2T5OLBSBBUHJP6/","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KRV2C5DATXBHG6TF6CEEX54KZ75THQS3/","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UF56LYB27LHEIFJTFHU3M75NMNNK2SCG/","source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-31800","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}