{"id":"CVE-2021-21342","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-21342","generatedAt":"2026-11-05T01:35:27.656Z","title":"In XStream before version 1.4.16, there is a vulnerability where the processed stream at unmarshalling time contains type information to recreate the formerly written objects.","description":"XStream is a Java library to serialize objects to XML and back again. In XStream before version 1.4.16, there is a vulnerability where the processed stream at unmarshalling time contains type information to recreate the formerly written objects. XStream creates therefore new instances based on these type information. An attacker can manipulate the processed input stream and replace or inject objects, that result in a server-side forgery request. No user is affected, who followed the recommendation to setup XStream's security framework with a whitelist limited to the minimal required types. If you rely on XStream's default blacklist of the Security Framework, you will have to use at least version 1.4.16.","published":"2021-03-23T00:15:12.000Z","lastModified":"2026-10-07T19:17:20.000Z","status":"Analyzed","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":9.1,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"},"cwe":["CWE-502","CWE-918"],"affected":["netapp/oncommand insight","apache/activemq","apache/jmeter","xstream/xstream","debian/debian linux","fedoraproject/fedora","oracle/banking enterprise default management","oracle/banking platform","oracle/banking virtual account management","oracle/business activity monitoring","oracle/communications brm - elastic charging engine","oracle/communications policy management","oracle/communications unified inventory management","oracle/retail xstore point of service","oracle/webcenter portal"],"epss":{"score":0.4999,"percentile":0.98903,"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 50.0%, higher than 99% of all known CVEs. Patch or mitigate before the next change window."},"changes":[],"references":[{"url":"http://x-stream.github.io/changes.html#1.4.16","tags":["Release Notes","Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://github.com/x-stream/xstream/security/advisories/GHSA-hvv8-336g-rx3m","tags":["Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://lists.apache.org/thread.html/r8244fd0831db894d5e89911ded9c72196d395a90ae655414d23ed0dd%40%3Cusers.activemq.apache.org%3E","tags":["Issue Tracking","Mailing List","Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://lists.apache.org/thread.html/r9ac71b047767205aa22e3a08cb33f3e0586de6b2fac48b425c6e16b0%40%3Cdev.jmeter.apache.org%3E","tags":["Issue Tracking","Mailing List","Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://lists.debian.org/debian-lts-announce/2021/04/msg00002.html","tags":["Mailing List","Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/22KVR6B5IZP3BGQ3HPWIO2FWWCKT3DHP/","tags":["Mailing List","Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PVPHZA7VW2RRSDCOIPP2W6O5ND254TU7/","tags":["Mailing List","Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGXIU3YDPG6OGTDHMBLAFN7BPBERXREB/","tags":["Mailing List","Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://security.netapp.com/advisory/ntap-20210430-0002/","tags":["Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://www.debian.org/security/2021/dsa-5004","tags":["Mailing List","Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://www.oracle.com//security-alerts/cpujul2021.html","tags":["Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://www.oracle.com/security-alerts/cpujan2022.html","tags":["Not Applicable","Patch","Vendor Advisory"],"source":"security-advisories@github.com"},{"url":"https://www.oracle.com/security-alerts/cpuoct2021.html","tags":["Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://x-stream.github.io/CVE-2021-21342.html","tags":["Exploit","Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://x-stream.github.io/security.html#workaround","tags":["Mitigation","Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"http://x-stream.github.io/changes.html#1.4.16","tags":["Release Notes","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/x-stream/xstream/security/advisories/GHSA-hvv8-336g-rx3m","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.apache.org/thread.html/r8244fd0831db894d5e89911ded9c72196d395a90ae655414d23ed0dd%40%3Cusers.activemq.apache.org%3E","tags":["Issue Tracking","Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.apache.org/thread.html/r9ac71b047767205aa22e3a08cb33f3e0586de6b2fac48b425c6e16b0%40%3Cdev.jmeter.apache.org%3E","tags":["Issue Tracking","Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2021/04/msg00002.html","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/22KVR6B5IZP3BGQ3HPWIO2FWWCKT3DHP/","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/PVPHZA7VW2RRSDCOIPP2W6O5ND254TU7/","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/QGXIU3YDPG6OGTDHMBLAFN7BPBERXREB/","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.netapp.com/advisory/ntap-20210430-0002/","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.debian.org/security/2021/dsa-5004","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.oracle.com//security-alerts/cpujul2021.html","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.oracle.com/security-alerts/cpujan2022.html","tags":["Not Applicable","Patch","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.oracle.com/security-alerts/cpuoct2021.html","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://x-stream.github.io/CVE-2021-21342.html","tags":["Exploit","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://x-stream.github.io/security.html#workaround","tags":["Mitigation","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-21342","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."}