{"id":"CVE-2021-22898","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-22898","generatedAt":"2026-10-27T22:32:51.107Z","title":"curl 7.7 through 7.76.1 suffers from an information disclosure when the `-t` command line option, known as `CURLOPT_TELNETOPTIONS` in libcurl, is used to send variable=content pairs to TELNET servers.","description":"curl 7.7 through 7.76.1 suffers from an information disclosure when the `-t` command line option, known as `CURLOPT_TELNETOPTIONS` in libcurl, is used to send variable=content pairs to TELNET servers. Due to a flaw in the option parser for sending NEW_ENV variables, libcurl could be made to pass on uninitialized data from a stack based buffer to the server, resulting in potentially revealing sensitive internal information to the server using a clear-text network protocol.","published":"2021-06-11T16:15:11.000Z","lastModified":"2026-10-14T11:16:53.000Z","status":"Modified","sourceIdentifier":"support@hackerone.com","cvss":{"version":"3.1","score":3.1,"severity":"LOW","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N"},"cwe":["CWE-200","CWE-909"],"affected":["haxx/curl","debian/debian linux","fedoraproject/fedora","oracle/communications cloud native core binding support function","oracle/communications cloud native core network function cloud native environment","oracle/communications cloud native core network repository function","oracle/communications cloud native core network slice selection function","oracle/communications cloud native core service communication proxy","oracle/essbase","oracle/mysql server","siemens/sinec infrastructure network services","splunk/universal forwarder"],"epss":{"score":0.04507,"percentile":0.91447,"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":"low","text":"Lower severity and a low EPSS score (4.51%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"http://www.openwall.com/lists/oss-security/2021/07/21/4","tags":["Mailing List","Patch","Third Party Advisory"],"source":"support@hackerone.com"},{"url":"https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf","tags":["Patch","Third Party Advisory"],"source":"support@hackerone.com"},{"url":"https://curl.se/docs/CVE-2021-22898.html","tags":["Exploit","Patch","Vendor Advisory"],"source":"support@hackerone.com"},{"url":"https://github.com/curl/curl/commit/39ce47f219b09c380b81f89fe54ac586c8db6bde","tags":["Patch","Third Party Advisory"],"source":"support@hackerone.com"},{"url":"https://hackerone.com/reports/1176461","tags":["Exploit","Issue Tracking","Patch","Third Party Advisory"],"source":"support@hackerone.com"},{"url":"https://lists.apache.org/thread.html/rc713534b10f9daeee2e0990239fa407e2118e4aa9e88a7041177497c%40%3Cissues.guacamole.apache.org%3E","tags":["Mailing List","Third Party Advisory"],"source":"support@hackerone.com"},{"url":"https://lists.debian.org/debian-lts-announce/2021/08/msg00017.html","tags":["Mailing List","Third Party Advisory"],"source":"support@hackerone.com"},{"url":"https://lists.debian.org/debian-lts-announce/2022/08/msg00017.html","tags":["Third Party Advisory"],"source":"support@hackerone.com"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FRUCW2UVNYUDZF72DQLFQR4PJEC6CF7V/","tags":["Mailing List","Third Party Advisory"],"source":"support@hackerone.com"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/POOC3UV7V6L4CJ5KA2PTWTNUV5Y72T3Q/","tags":["Mailing List","Third Party Advisory"],"source":"support@hackerone.com"},{"url":"https://www.debian.org/security/2022/dsa-5197","tags":["Third Party Advisory"],"source":"support@hackerone.com"},{"url":"https://www.oracle.com//security-alerts/cpujul2021.html","tags":["Patch","Third Party Advisory"],"source":"support@hackerone.com"},{"url":"https://www.oracle.com/security-alerts/cpuapr2022.html","tags":["Patch","Third Party Advisory"],"source":"support@hackerone.com"},{"url":"https://www.oracle.com/security-alerts/cpujan2022.html","tags":["Patch","Third Party Advisory"],"source":"support@hackerone.com"},{"url":"http://www.openwall.com/lists/oss-security/2021/07/21/4","tags":["Mailing List","Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://curl.se/docs/CVE-2021-22898.html","tags":["Exploit","Patch","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/curl/curl/commit/39ce47f219b09c380b81f89fe54ac586c8db6bde","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://hackerone.com/reports/1176461","tags":["Exploit","Issue Tracking","Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.apache.org/thread.html/rc713534b10f9daeee2e0990239fa407e2118e4aa9e88a7041177497c%40%3Cissues.guacamole.apache.org%3E","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2021/08/msg00017.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2022/08/msg00017.html","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FRUCW2UVNYUDZF72DQLFQR4PJEC6CF7V/","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/POOC3UV7V6L4CJ5KA2PTWTNUV5Y72T3Q/","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.debian.org/security/2022/dsa-5197","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.oracle.com//security-alerts/cpujul2021.html","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.oracle.com/security-alerts/cpuapr2022.html","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.oracle.com/security-alerts/cpujan2022.html","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-398330.html","source":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-22898","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."}