{"id":"CVE-2021-29922","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-29922","generatedAt":"2026-10-27T22:31:56.574Z","title":"library/std/src/net/parser.rs in Rust before 1.53.0 does not properly consider extraneous zero characters at the beginning of an IP address string, which (in some situations) allows attackers to bypass access control that is based on IP addresses,…","description":"library/std/src/net/parser.rs in Rust before 1.53.0 does not properly consider extraneous zero characters at the beginning of an IP address string, which (in some situations) allows attackers to bypass access control that is based on IP addresses, because of unexpected octal interpretation.","published":"2021-08-07T17:15:07.000Z","lastModified":"2026-06-17T03:48:27.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.1","score":9.1,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H"},"cwe":[],"affected":["rust-lang/rust"],"epss":{"score":0.02623,"percentile":0.85367,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (2.62%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://defcon.org/html/defcon-29/dc-29-speakers.html#kaoudis","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://doc.rust-lang.org/beta/std/net/struct.Ipv4Addr.html","tags":["Vendor Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/rust-lang/rust/issues/83648","tags":["Exploit","Issue Tracking","Patch","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/rust-lang/rust/pull/83652","tags":["Patch","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/sickcodes/security/blob/master/advisories/SICK-2021-015.md","tags":["Exploit","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://security.gentoo.org/glsa/202210-09","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://defcon.org/html/defcon-29/dc-29-speakers.html#kaoudis","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://doc.rust-lang.org/beta/std/net/struct.Ipv4Addr.html","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/rust-lang/rust/issues/83648","tags":["Exploit","Issue Tracking","Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/rust-lang/rust/pull/83652","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/sickcodes/security/blob/master/advisories/SICK-2021-015.md","tags":["Exploit","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.gentoo.org/glsa/202210-09","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-29922","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."}