{"answers":{"affected":"2 open source packages ship an affected version, including nginx and nginx-gateway. It affects 13 products.","exploited":"There is no known exploitation of CVE-2021-23017 in the wild and no public exploit code.","fix":"Upgrade nginx to 1.20.1 or later.","what":"CVE-2021-23017 is a high-severity memory corruption vulnerability in Fedoraproject Fedora, published on 1 Jun 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-2021-23017 and fix it if it is affected.\n\nWhat it is: CVE-2021-23017 is a high-severity memory corruption vulnerability in Fedoraproject Fedora, published on 1 Jun 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-2021-23017 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- nginx (Bitnami): affected from 0.6.18; fixed in 1.20.1\n- nginx-gateway (Bitnami): affected from 0.6.18; fixed in 1.20.1\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-2021-23017/ (Markdown: https://insights.sbomify.com/CVE-2021-23017/index.md)","id":"CVE-2021-23017","markdown":"https://insights.sbomify.com/CVE-2021-23017/index.md","name":"CVE-2021-23017","record":{"aliases":["ALPINE-CVE-2021-23017","ALSA-2021:2259","ALSA-2021:2290","ALSA-2022:0323","BIT-nginx-2021-23017","BIT-nginx-gateway-2021-23017","CLEANSTART-2026-WB96831","CLSA-2021-1632261741","CLSA-2021-1632261762","CLSA-2021-1634922789","CLSA-2021-1634922818","CLSA-2021-1635459350","CLSA-2021-1635459358","CLSA-2022-1646060645","CLSA-2022-1646085758","DEBIAN-CVE-2021-23017","DLA-2670-1","DSA-4921-1","GHSA-83p9-mcpm-374v","MGASA-2021-0301","OESA-2021-1225","RHBA-2021:2955","RHSA-2021:2258","RHSA-2021:2259","RHSA-2021:2278","RHSA-2021:2290","RHSA-2022:0323","RLSA-2021:2259","RLSA-2021:2290","RLSA-2022:0323","SUSE-SU-2021:1792-1","SUSE-SU-2021:1814-1","SUSE-SU-2021:1815-1","SUSE-SU-2021:1839-1","UBUNTU-CVE-2021-23017","USN-4967-1","USN-4967-2","openSUSE-SU-2021:0835-1","openSUSE-SU-2021:1815-1"],"analysis":{"component_type":"server_software","fix_type":"patch","impacts":["denial_of_service","code_execution"],"network_reachable":"yes","non_default_config":true,"product_category":"Nginx web server","requires_auth":"none","summary":"An attacker forging DNS UDP packets can trigger a 1-byte memory overwrite in Nginx resolver, causing worker crashes or potential code execution.","user_interaction":"not_required","vuln_class":"memory_corruption"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"f5","cpe":[{"product":"nginx","vendor":"f5"},{"product":"fedora","vendor":"fedoraproject"},{"product":"ontap_select_deploy_administration_utility","vendor":"netapp"},{"product":"openresty","vendor":"openresty"},{"product":"blockchain_platform","vendor":"oracle"},{"product":"communications_control_plane_monitor","vendor":"oracle"},{"product":"communications_fraud_monitor","vendor":"oracle"},{"product":"communications_operations_monitor","vendor":"oracle"},{"product":"communications_session_border_controller","vendor":"oracle"},{"product":"enterprise_communications_broker","vendor":"oracle"},{"product":"enterprise_session_border_controller","vendor":"oracle"},{"product":"enterprise_telephony_fraud_monitor","vendor":"oracle"},{"product":"goldengate","vendor":"oracle"}],"cvss":{"score":7.7,"severity":"high","source":"nvd","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L","version":"3.1"},"cwes":[{"id":"CWE-193","name":"Off-by-one Error"}],"description":"A security issue in nginx resolver was identified, which might allow an attacker who is able to forge UDP packets from the DNS server to cause 1-byte memory overwrite, resulting in worker process crash or potential other impact.","ecosystems":["AlmaLinux:8","Bitnami","Red Hat:ansible_automation_platform:4.2::el7","Red Hat:ansible_automation_platform:4.2::el8","Red Hat:enterprise_linux:8::appstream","Red Hat:rhel_eus:8.1::appstream","Red Hat:rhel_eus:8.2::appstream","Red Hat:rhel_software_collections:3::el7","Rocky Linux:8","SUSE:Enterprise Storage 6","SUSE:Linux Enterprise High Performance Computing 15 SP1-ESPOS","SUSE:Linux Enterprise High Performance Computing 15 SP1-LTSS","SUSE:Linux Enterprise High Performance Computing 15-ESPOS","SUSE:Linux Enterprise High Performance Computing 15-LTSS","SUSE:Linux Enterprise Module for Server Applications 15 SP2","SUSE:Linux Enterprise Module for Server Applications 15 SP3","SUSE:Linux Enterprise Server 15 SP1-BCL","SUSE:Linux Enterprise Server 15 SP1-LTSS","SUSE:Linux Enterprise Server 15-LTSS","SUSE:Linux Enterprise Server for SAP Applications 15","SUSE:Linux Enterprise Server for SAP Applications 15 SP1","SUSE:Manager Proxy 4.0","SUSE:Manager Retail Branch Server 4.0","SUSE:Manager Server 4.0","openSUSE:Leap 15.2","openSUSE:Leap 15.3"],"exploits":{"exploitdb":1,"first_seen":"2021-12-17","github_poc":9,"max_poc_stars":136,"metasploit":0,"nuclei":0,"refs":[{"date":"2022-06-30T04:39:58Z","kind":"github_poc","ref":"https://github.com/M507/CVE-2021-23017-PoC","stars":136,"title":"PoC for Nginx 0.6.18 - 1.20.0 Memory Overwrite Vulnerability CVE-2021-23017"},{"date":"2021-12-17T09:53:39Z","kind":"github_poc","ref":"https://github.com/niandy/nginx-patch","stars":1,"title":"nginx 1.15.10 patch against cve-2021-23017  (ingress version)"},{"date":"2023-07-20T05:39:01Z","kind":"github_poc","ref":"https://github.com/lakshit1212/CVE-2021-23017-PoC","stars":1,"title":null},{"date":"2024-12-08T09:47:52Z","kind":"github_poc","ref":"https://github.com/z3usx01/CVE-2021-23017-POC","stars":1,"title":"The issue only affects nginx if the \"resolver\" directive is used in the configuration file. Further, the attack is only possible if an attacker is able to forge UDP packets from the DNS server."},{"date":"2025-09-04T09:49:22Z","kind":"github_poc","ref":"https://github.com/6lj/EVIL-CVE-2021-23017-Update-2025","stars":1,"title":"vulnerability in NGINX servers (versions 0.6.18–1.20.0). The scripts aim to cause a Denial of Service (DoS) by sending malicious DNS responses, with enhancements to bypass firewalls."},{"date":"2022-07-11","kind":"exploitdb","ref":"50973","stars":null,"title":"Nginx 1.20.0 - Denial of Service (DOS)"},{"date":"2023-10-21T04:24:02Z","kind":"github_poc","ref":"https://github.com/ShivamDey/CVE-2021-23017","stars":0,"title":null},{"date":"2025-01-30T11:05:40Z","kind":"github_poc","ref":"https://github.com/lukwagoasuman/-home-lukewago-Downloads-CVE-2021-23017-Nginx-1.14","stars":0,"title":null}],"tier":"poc_unverified"},"has_fix":true,"headline":"Memory corruption in Nginx Web Server, Nginx Plus","id":"CVE-2021-23017","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Bitnami","product":"fedoraproject:fedora","products":["fedoraproject:fedora","netapp:ontap_select_deploy_administration_utility"],"type":"memory_corruption","year":"2021"},"n_packages":166,"n_references":14,"next":{"headline":"Weak cryptography in Nginx Controller","id":"CVE-2021-23018"},"packages":[{"ecosystem":"Bitnami","fixed":["1.20.1"],"introduced":["0.6.18"],"last_affected":[],"package":"nginx","purl":"pkg:bitnami/nginx","source":"BIT-nginx-2021-23017"},{"ecosystem":"Bitnami","fixed":["1.20.1"],"introduced":["0.6.18"],"last_affected":[],"package":"nginx-gateway","purl":"pkg:bitnami/nginx-gateway","source":"BIT-nginx-gateway-2021-23017"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.16.1-2.module_el8.4.0+2470+68135136.1.alma"],"introduced":["0"],"last_affected":[],"package":"nginx","purl":"pkg:rpm/almalinux/nginx","source":"ALSA-2021:2290"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.16.1-2.module_el8.5.0+35+6a1225c3.1.alma"],"introduced":["0"],"last_affected":[],"package":"nginx","purl":"pkg:rpm/almalinux/nginx","source":"ALSA-2021:2290"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.18.0-3.module_el8.4.0+2472+f736ed63.1.alma"],"introduced":["0"],"last_affected":[],"package":"nginx","purl":"pkg:rpm/almalinux/nginx","source":"ALSA-2021:2259"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.18.0-3.module_el8.5.0+36+48437aab.1.alma"],"introduced":["0"],"last_affected":[],"package":"nginx","purl":"pkg:rpm/almalinux/nginx","source":"ALSA-2021:2259"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.20.1-1.module_el8.5.0+2611+ab304644.alma"],"introduced":["0"],"last_affected":[],"package":"nginx","purl":"pkg:rpm/almalinux/nginx","source":"ALSA-2022:0323"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.20.1-1.module_el8.6.0+2782+a022aca3.alma"],"introduced":["0"],"last_affected":[],"package":"nginx","purl":"pkg:rpm/almalinux/nginx","source":"ALSA-2022:0323"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.16.1-2.module_el8.4.0+2470+68135136.1.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-all-modules","purl":"pkg:rpm/almalinux/nginx-all-modules","source":"ALSA-2021:2290"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.18.0-3.module_el8.4.0+2472+f736ed63.1.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-all-modules","purl":"pkg:rpm/almalinux/nginx-all-modules","source":"ALSA-2021:2259"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.20.1-1.module_el8.5.0+2611+ab304644.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-all-modules","purl":"pkg:rpm/almalinux/nginx-all-modules","source":"ALSA-2022:0323"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.20.1-1.module_el8.6.0+2782+a022aca3.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-all-modules","purl":"pkg:rpm/almalinux/nginx-all-modules","source":"ALSA-2022:0323"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.16.1-2.module_el8.4.0+2470+68135136.1.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-filesystem","purl":"pkg:rpm/almalinux/nginx-filesystem","source":"ALSA-2021:2290"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.18.0-3.module_el8.4.0+2472+f736ed63.1.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-filesystem","purl":"pkg:rpm/almalinux/nginx-filesystem","source":"ALSA-2021:2259"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.20.1-1.module_el8.5.0+2611+ab304644.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-filesystem","purl":"pkg:rpm/almalinux/nginx-filesystem","source":"ALSA-2022:0323"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.20.1-1.module_el8.6.0+2782+a022aca3.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-filesystem","purl":"pkg:rpm/almalinux/nginx-filesystem","source":"ALSA-2022:0323"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.16.1-2.module_el8.4.0+2470+68135136.1.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-mod-http-image-filter","purl":"pkg:rpm/almalinux/nginx-mod-http-image-filter","source":"ALSA-2021:2290"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.16.1-2.module_el8.5.0+35+6a1225c3.1.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-mod-http-image-filter","purl":"pkg:rpm/almalinux/nginx-mod-http-image-filter","source":"ALSA-2021:2290"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.18.0-3.module_el8.4.0+2472+f736ed63.1.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-mod-http-image-filter","purl":"pkg:rpm/almalinux/nginx-mod-http-image-filter","source":"ALSA-2021:2259"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.18.0-3.module_el8.5.0+36+48437aab.1.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-mod-http-image-filter","purl":"pkg:rpm/almalinux/nginx-mod-http-image-filter","source":"ALSA-2021:2259"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.20.1-1.module_el8.5.0+2611+ab304644.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-mod-http-image-filter","purl":"pkg:rpm/almalinux/nginx-mod-http-image-filter","source":"ALSA-2022:0323"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.20.1-1.module_el8.6.0+2782+a022aca3.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-mod-http-image-filter","purl":"pkg:rpm/almalinux/nginx-mod-http-image-filter","source":"ALSA-2022:0323"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.16.1-2.module_el8.4.0+2470+68135136.1.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-mod-http-perl","purl":"pkg:rpm/almalinux/nginx-mod-http-perl","source":"ALSA-2021:2290"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.16.1-2.module_el8.5.0+35+6a1225c3.1.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-mod-http-perl","purl":"pkg:rpm/almalinux/nginx-mod-http-perl","source":"ALSA-2021:2290"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.18.0-3.module_el8.4.0+2472+f736ed63.1.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-mod-http-perl","purl":"pkg:rpm/almalinux/nginx-mod-http-perl","source":"ALSA-2021:2259"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.18.0-3.module_el8.5.0+36+48437aab.1.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-mod-http-perl","purl":"pkg:rpm/almalinux/nginx-mod-http-perl","source":"ALSA-2021:2259"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.20.1-1.module_el8.5.0+2611+ab304644.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-mod-http-perl","purl":"pkg:rpm/almalinux/nginx-mod-http-perl","source":"ALSA-2022:0323"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.20.1-1.module_el8.6.0+2782+a022aca3.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-mod-http-perl","purl":"pkg:rpm/almalinux/nginx-mod-http-perl","source":"ALSA-2022:0323"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.16.1-2.module_el8.4.0+2470+68135136.1.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-mod-http-xslt-filter","purl":"pkg:rpm/almalinux/nginx-mod-http-xslt-filter","source":"ALSA-2021:2290"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.16.1-2.module_el8.5.0+35+6a1225c3.1.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-mod-http-xslt-filter","purl":"pkg:rpm/almalinux/nginx-mod-http-xslt-filter","source":"ALSA-2021:2290"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.18.0-3.module_el8.4.0+2472+f736ed63.1.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-mod-http-xslt-filter","purl":"pkg:rpm/almalinux/nginx-mod-http-xslt-filter","source":"ALSA-2021:2259"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.18.0-3.module_el8.5.0+36+48437aab.1.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-mod-http-xslt-filter","purl":"pkg:rpm/almalinux/nginx-mod-http-xslt-filter","source":"ALSA-2021:2259"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.20.1-1.module_el8.5.0+2611+ab304644.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-mod-http-xslt-filter","purl":"pkg:rpm/almalinux/nginx-mod-http-xslt-filter","source":"ALSA-2022:0323"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.20.1-1.module_el8.6.0+2782+a022aca3.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-mod-http-xslt-filter","purl":"pkg:rpm/almalinux/nginx-mod-http-xslt-filter","source":"ALSA-2022:0323"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.16.1-2.module_el8.4.0+2470+68135136.1.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-mod-mail","purl":"pkg:rpm/almalinux/nginx-mod-mail","source":"ALSA-2021:2290"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.16.1-2.module_el8.5.0+35+6a1225c3.1.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-mod-mail","purl":"pkg:rpm/almalinux/nginx-mod-mail","source":"ALSA-2021:2290"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.18.0-3.module_el8.4.0+2472+f736ed63.1.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-mod-mail","purl":"pkg:rpm/almalinux/nginx-mod-mail","source":"ALSA-2021:2259"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.18.0-3.module_el8.5.0+36+48437aab.1.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-mod-mail","purl":"pkg:rpm/almalinux/nginx-mod-mail","source":"ALSA-2021:2259"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.20.1-1.module_el8.5.0+2611+ab304644.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-mod-mail","purl":"pkg:rpm/almalinux/nginx-mod-mail","source":"ALSA-2022:0323"},{"ecosystem":"AlmaLinux:8","fixed":["1:1.20.1-1.module_el8.6.0+2782+a022aca3.alma"],"introduced":["0"],"last_affected":[],"package":"nginx-mod-mail","purl":"pkg:rpm/almalinux/nginx-mod-mail","source":"ALSA-2022:0323"}],"prev":{"headline":"Information disclosure in BIG-IP APM","id":"CVE-2021-23016"},"products":["Nginx Web Server, Nginx Plus"],"published":"2021-06-01","related":[{"cvss_score":7.8,"headline":"Path traversal in n/a","id":"CVE-2016-1247","kev_date_added":null,"published":"2016-11-29"},{"cvss_score":7.5,"headline":"Memory corruption in n/a","id":"CVE-2014-0088","kev_date_added":null,"published":"2014-04-29"},{"cvss_score":7.5,"headline":"Memory corruption in n/a","id":"CVE-2014-0133","kev_date_added":null,"published":"2014-03-28"},{"cvss_score":7.5,"headline":"Security feature bypass in n/a","id":"CVE-2013-4547","kev_date_added":null,"published":"2013-11-23"},{"cvss_score":7.5,"headline":"Information disclosure in n/a","id":"CVE-2013-0337","kev_date_added":null,"published":"2013-10-27"},{"cvss_score":7.5,"headline":"Integer overflow in n/a","id":"CVE-2013-2028","kev_date_added":null,"published":"2013-07-18"}],"sources":[{"class":"attribution","licence":"MIT","name":"AlmaLinux","prefix":"ALSA"},{"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":"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)"},{"class":"attribution","licence":"GPL-2.0-or-later","name":"Exploit-DB"},{"class":"open","licence":"CC0","name":"PoC-in-GitHub"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2024-08-03","vendors":["n/a"]},"summary":"An attacker forging DNS UDP packets can trigger a 1-byte memory overwrite in Nginx resolver, causing worker crashes or potential code execution.","url":"https://insights.sbomify.com/CVE-2021-23017/"}