{"answers":{"affected":"15 open source packages ship an affected version, including github.com/nats-io/jwt, nats and github.com/nats-io/jwt/v2. It affects 2 products.","exploited":"There is no known exploitation of CVE-2021-3127 in the wild and no public exploit code.","fix":"Upgrade github.com/nats-io/jwt to 1.2.3-0.20210314221642-a826c77dc9d2 or later.","what":"CVE-2021-3127 is a high-severity missing authorization vulnerability in n/a, published on 16 Mar 2021. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2021-3127 and fix it if it is affected.\n\nWhat it is: CVE-2021-3127 is a high-severity missing authorization vulnerability in n/a, published on 16 Mar 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2021-3127 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- github.com/nats-io/jwt (Go): affected all versions up to 1.2.2; no fix listed\n- github.com/nats-io/jwt (Go): affected all versions up to 1.2.2; no fix listed\n- github.com/nats-io/jwt (Go): affected all versions; fixed in 1.2.3-0.20210314221642-a826c77dc9d2\n- github.com/nats-io/jwt (Go): affected all versions; fixed in 1.2.3-0.20210314221642-a826c77dc9d2\n- github.com/nats-io/jwt (Go): affected all versions; fixed in 1.2.3-0.20210314221642-a826c77dc9d2\n- nats (Bitnami): affected from 2.0.0; fixed in 2.2.0\n- github.com/nats-io/jwt/v2 (Go): affected all versions; fixed in 2.0.1\n- github.com/nats-io/jwt/v2 (Go): affected all versions; fixed in 2.0.1\n- github.com/nats-io/jwt/v2 (Go): affected all versions; fixed in 2.0.1\n- github.com/nats-io/jwt/v2 (Go): affected all versions; fixed in 2.0.1\n- github.com/nats-io/jwt/v2 (Go): affected all versions; fixed in 2.0.1\n- github.com/nats-io/nats-server/v2 (Go): affected all versions; fixed in 2.2.0\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2021-3127/ (Markdown: https://insights.sbomify.com/CVE-2021-3127/index.md)","id":"CVE-2021-3127","markdown":"https://insights.sbomify.com/CVE-2021-3127/index.md","name":"CVE-2021-3127","record":{"aliases":["BIT-nats-2021-3127","DEBIAN-CVE-2021-3127","GHSA-62mh-w5cv-p88c","GHSA-9r5x-fjv3-q6h4","GHSA-j756-f273-xhp4","GO-2022-0386","UBUNTU-CVE-2021-3127"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"NATS messaging server","requires_auth":"none","summary":"Attackers can bypass access controls in NATS Server due to mishandled Import Token bindings, potentially gaining unauthorized access to resources.","user_interaction":"not_required","vuln_class":"missing_authorization"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"mitre","cpe":[{"product":"nats-server","vendor":"linuxfoundation"},{"product":"jwt_library","vendor":"nats"}],"cvss":{"score":7.5,"severity":"high","source":"nvd","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","version":"3.1"},"cwes":[{"id":"CWE-755","name":"Improper Handling of Exceptional Conditions"}],"description":"NATS Server 2.x before 2.2.0 and JWT library before 2.0.1 have Incorrect Access Control because Import Token bindings are mishandled.","ecosystems":["Bitnami","Go"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"nats-io/jwt not enforcing checking of Import token permissions","id":"CVE-2021-3127","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Bitnami","product":null,"products":[],"type":"missing_authorization","year":"2021"},"n_packages":15,"n_references":1,"next":{"headline":"Denial of service in n/a","id":"CVE-2021-3128"},"packages":[{"ecosystem":"Bitnami","fixed":["2.2.0"],"introduced":["2.0.0"],"last_affected":[],"package":"nats","purl":"pkg:bitnami/nats","source":"BIT-nats-2021-3127"},{"ecosystem":"Go","fixed":[],"introduced":["0"],"last_affected":["1.2.2"],"package":"github.com/nats-io/jwt","purl":null,"source":"GHSA-62mh-w5cv-p88c"},{"ecosystem":"Go","fixed":[],"introduced":["0"],"last_affected":["1.2.2"],"package":"github.com/nats-io/jwt","purl":"pkg:golang/github.com/nats-io/jwt","source":"GHSA-62mh-w5cv-p88c"},{"ecosystem":"Go","fixed":["1.2.3-0.20210314221642-a826c77dc9d2"],"introduced":["0"],"last_affected":[],"package":"github.com/nats-io/jwt","purl":null,"source":"GHSA-9r5x-fjv3-q6h4"},{"ecosystem":"Go","fixed":["1.2.3-0.20210314221642-a826c77dc9d2"],"introduced":["0"],"last_affected":[],"package":"github.com/nats-io/jwt","purl":"pkg:golang/github.com/nats-io/jwt","source":"GHSA-9r5x-fjv3-q6h4"},{"ecosystem":"Go","fixed":["1.2.3-0.20210314221642-a826c77dc9d2"],"introduced":["0"],"last_affected":[],"package":"github.com/nats-io/jwt","purl":"pkg:golang/github.com/nats-io/jwt","source":"GO-2022-0386"},{"ecosystem":"Go","fixed":["2.0.1"],"introduced":["0"],"last_affected":[],"package":"github.com/nats-io/jwt/v2","purl":null,"source":"GHSA-62mh-w5cv-p88c"},{"ecosystem":"Go","fixed":["2.0.1"],"introduced":["0"],"last_affected":[],"package":"github.com/nats-io/jwt/v2","purl":"pkg:golang/github.com/nats-io/jwt/v2","source":"GHSA-62mh-w5cv-p88c"},{"ecosystem":"Go","fixed":["2.0.1"],"introduced":["0"],"last_affected":[],"package":"github.com/nats-io/jwt/v2","purl":null,"source":"GHSA-9r5x-fjv3-q6h4"},{"ecosystem":"Go","fixed":["2.0.1"],"introduced":["0"],"last_affected":[],"package":"github.com/nats-io/jwt/v2","purl":"pkg:golang/github.com/nats-io/jwt/v2","source":"GHSA-9r5x-fjv3-q6h4"},{"ecosystem":"Go","fixed":["2.0.1"],"introduced":["0"],"last_affected":[],"package":"github.com/nats-io/jwt/v2","purl":"pkg:golang/github.com/nats-io/jwt/v2","source":"GO-2022-0386"},{"ecosystem":"Go","fixed":["2.2.0"],"introduced":["0"],"last_affected":[],"package":"github.com/nats-io/nats-server/v2","purl":null,"source":"GHSA-9r5x-fjv3-q6h4"},{"ecosystem":"Go","fixed":["2.2.0"],"introduced":["0"],"last_affected":[],"package":"github.com/nats-io/nats-server/v2","purl":"pkg:golang/github.com/nats-io/nats-server/v2","source":"GHSA-9r5x-fjv3-q6h4"},{"ecosystem":"Go","fixed":["2.2.0"],"introduced":["0"],"last_affected":[],"package":"github.com/nats-io/nats-server/v2","purl":null,"source":"GHSA-j756-f273-xhp4"},{"ecosystem":"Go","fixed":["2.2.0"],"introduced":["0"],"last_affected":[],"package":"github.com/nats-io/nats-server/v2","purl":"pkg:golang/github.com/nats-io/nats-server/v2","source":"GHSA-j756-f273-xhp4"}],"prev":{"headline":"Denial of service in n/a","id":"CVE-2021-3125"},"products":["n/a"],"published":"2021-03-16","related":[{"cvss_score":9.8,"headline":"NATS nats-server allows directory traversal via unintended path to a management action","id":"CVE-2022-28357","kev_date_added":null,"published":"2023-09-19"},{"cvss_score":8.8,"headline":"NATS Server: Route API Auth Bypass","id":"CVE-2026-58253","kev_date_added":null,"published":"2026-07-08"},{"cvss_score":8.8,"headline":"Incorrect Authorization in NATS nats-server","id":"CVE-2022-24450","kev_date_added":null,"published":"2022-02-08"},{"cvss_score":8.6,"headline":"NATS has MQTT plaintext password disclosure","id":"CVE-2026-33216","kev_date_added":null,"published":"2026-03-25"},{"cvss_score":7.7,"headline":"NATS Server: Remote crash via integer overflow in Connz pagination","id":"CVE-2026-58207","kev_date_added":null,"published":"2026-07-08"},{"cvss_score":7.5,"headline":"NATS Server: MQTT partial CONNECT packets can exhaust pre-auth memory","id":"CVE-2026-58210","kev_date_added":null,"published":"2026-07-08"},{"cvss_score":7.5,"headline":"NATS Server: Pre-auth server crash via double INFO in leafnode handshake","id":"CVE-2026-58250","kev_date_added":null,"published":"2026-07-08"}],"sources":[{"class":"attribution","licence":"Apache-2.0","name":"Bitnami","prefix":"BIT"},{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"CC BY 4.0","name":"Go Vulnerability Database","prefix":"GO"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2024-08-03","vendors":["n/a"]},"summary":"Attackers can bypass access controls in NATS Server due to mishandled Import Token bindings, potentially gaining unauthorized access to resources.","url":"https://insights.sbomify.com/CVE-2021-3127/"}