{"cve":"CVE-2021-21290","nvd":{"published":"2021-02-08T20:15:12.433","modified":"2026-10-08T22:17:04.713","status":"Modified","description":"Netty is an open-source, asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. In Netty before version 4.1.59.Final there is a vulnerability on Unix-like systems involving an insecure temp file. When netty's multipart decoders are used local information disclosure can occur via the local system temporary directory if temporary storing uploads on the disk is enabled. On unix-like systems, the temporary directory is shared between all user. As such, writing to this directory using APIs that do not explicitly set the file/directory permissions can lead to information disclosure. Of note, this does not impact modern MacOS Operating Systems. The method \"File.createTempFile\" on unix-like systems creates a random file, but, by default will create this file with the permissions \"-rw-r--r--\". Thus, if sensitive information is written to this file, other local users can read this information. This is the case in netty's \"AbstractDiskHttpData\" is vulnerable. This has been fixed in version 4.1.59.Final. As a workaround, one may specify your own \"java.io.tmpdir\" when you start the JVM or use \"DefaultHttpDataFactory.setBaseDir(...)\" to set the directory to something that is only readable by the current user.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N","score":5.5},"cwes":["CWE-668","CWE-378","CWE-379"],"references":["https://github.com/netty/netty/commit/c735357bf29d07856ad171c6611a2e1a0e0000ec","https://github.com/netty/netty/security/advisories/GHSA-5mcr-gq6c-3hq2","https://lists.apache.org/thread.html/r0053443ce19ff125981559f8c51cf66e3ab4350f47812b8cf0733a05%40%3Cdev.kafka.apache.org%3E","https://lists.apache.org/thread.html/r02e467123d45006a1dda20a38349e9c74c3a4b53e2e07be0939ecb3f%40%3Cdev.ranger.apache.org%3E","https://lists.apache.org/thread.html/r0857b613604c696bf9743f0af047360baaded48b1c75cf6945a083c5%40%3Cjira.kafka.apache.org%3E"],"products":["debian:debian_linux","netapp:active_iq_unified_manager","netapp:cloud_secure_agent","netapp:snapcenter","netty:netty","oracle:banking_corporate_lending_process_management","oracle:banking_credit_facilities_process_management","oracle:banking_trade_finance_process_management","oracle:communications_brm_-_elastic_charging_engine","oracle:communications_design_studio","oracle:communications_messaging_server","oracle:nosql_database","quarkus:quarkus"],"source":"nvd","synced_at":"2026-10-19T21:14:10.479542811+00:00"},"epss":{"cve":"CVE-2021-21290","score":0.01777,"percentile":0.78063,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-5mcr-gq6c-3hq2","url":"https://osv.dev/vulnerability/GHSA-5mcr-gq6c-3hq2","summary":"Local Information Disclosure Vulnerability in Netty on Unix-Like systems","modified":"2026-09-10T03:49:14.198330300Z","packages":[{"ecosystem":"Maven","name":"io.netty:netty-codec-http","purl":"pkg:maven/io.netty/netty-codec-http","ranges":[">=4.0.0 <4.1.59.Final"],"fixed":["4.1.59.Final"]},{"ecosystem":"Maven","name":"org.jboss.netty:netty","purl":"pkg:maven/org.jboss.netty/netty","ranges":["all versions"],"fixed":[]},{"ecosystem":"Maven","name":"io.netty:netty","purl":"pkg:maven/io.netty/netty","ranges":["all versions"],"fixed":[]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}