{"answers":{"affected":"1 open source package ship an affected version, including envoy. It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-43826 in the wild and no public exploit code.","fix":"Upgrade envoy to a fixed version for your release line: 1.18.6, 1.19.3, 1.20.2 or 1.21.1.","what":"CVE-2021-43826 is a high-severity use after free vulnerability in Envoyproxy Envoy, published on 22 Feb 2022. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2021-43826 and fix it if it is affected.\n\nWhat it is: CVE-2021-43826 is a high-severity use after free vulnerability in Envoyproxy Envoy, published on 22 Feb 2022. 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-2021-43826 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- envoy (Bitnami): affected all versions; fixed in 1.18.6, 1.19.3, 1.20.2, 1.21.1\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-2021-43826/ (Markdown: https://insights.sbomify.com/CVE-2021-43826/index.md)","id":"CVE-2021-43826","markdown":"https://insights.sbomify.com/CVE-2021-43826/index.md","name":"CVE-2021-43826","record":{"aliases":["BIT-envoy-2021-43826","GHSA-cmx3-fvgf-83mf"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":true,"product_category":"Envoy proxy","requires_auth":"none","summary":"Attackers can crash Envoy proxy by disconnecting downstream connections during upstream tunneling setup, requiring specific tunneling configuration.","user_interaction":"not_required","vuln_class":"use_after_free"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"envoy","vendor":"envoyproxy"}],"cvss":{"score":7.5,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-416","name":"Use After Free"}],"description":"Envoy is an open source edge and service proxy, designed for cloud-native applications. In affected versions of Envoy a crash occurs when configured for :ref:`upstream tunneling \u003cenvoy_v3_api_field_extensions.filters.network.tcp_proxy.v3.TcpProxy.tunneling_config\u003e` and the downstream connection disconnects while the the upstream connection or http/2 stream is still being established. There are no workarounds for this issue. Users are advised to upgrade.","ecosystems":["Bitnami"],"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":"Crash when tunneling TCP over HTTP in Envoy","id":"CVE-2021-43826","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Bitnami","product":"envoyproxy:envoy","products":["envoyproxy:envoy"],"type":"use_after_free","year":"2021"},"n_packages":1,"n_references":2,"next":{"headline":"Inline footnotes wrapped in \u003ca\u003e tags can cause errors in discourse-footnotes","id":"CVE-2021-43827"},"packages":[{"ecosystem":"Bitnami","fixed":["1.18.6","1.19.3","1.20.2","1.21.1"],"introduced":["0","1.19.0","1.20.0","1.21.0"],"last_affected":[],"package":"envoy","purl":"pkg:bitnami/envoy","source":"BIT-envoy-2021-43826"}],"prev":{"headline":"Use-after-free in Envoy","id":"CVE-2021-43825"},"products":["envoy"],"published":"2022-02-22","related":[{"cvss_score":10,"headline":"Trivial authentication bypass in Envoy","id":"CVE-2022-29226","kev_date_added":null,"published":"2022-06-09"},{"cvss_score":9.8,"headline":"Memory corruption in n/a","id":"CVE-2019-18801","kev_date_added":null,"published":"2019-12-13"},{"cvss_score":9.8,"headline":"Security feature bypass in n/a","id":"CVE-2019-18802","kev_date_added":null,"published":"2019-12-13"},{"cvss_score":8.8,"headline":"Information disclosure in n/a","id":"CVE-2020-35470","kev_date_added":null,"published":"2020-12-15"},{"cvss_score":8.6,"headline":"Envoy ext auth can be bypassed when Proxy protocol filter sets invalid UTF-8 metadata","id":"CVE-2024-23324","kev_date_added":null,"published":"2024-02-09"},{"cvss_score":8.6,"headline":"Envoy vulnerable to OAuth2 credentials exploit with permanent validity","id":"CVE-2023-35941","kev_date_added":null,"published":"2023-07-25"},{"cvss_score":8.6,"headline":"Incorrect handling of H2 GOAWAY + SETTINGS frames","id":"CVE-2021-39162","kev_date_added":null,"published":"2021-09-09"}],"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":"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":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2025-04-23","vendors":["envoyproxy"]},"summary":"Attackers can crash Envoy proxy by disconnecting downstream connections during upstream tunneling setup, requiring specific tunneling configuration.","url":"https://insights.sbomify.com/CVE-2021-43826/"}