{"answers":{"affected":"3 open source packages ship an affected version, including mitmproxy. It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-39214 in the wild and no public exploit code.","fix":"Upgrade mitmproxy to 7.0.3 or later.","what":"CVE-2021-39214 is a high-severity vulnerability in mitmproxy, published on 16 Sep 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-2021-39214 and fix it if it is affected.\n\nWhat it is: CVE-2021-39214 is a high-severity vulnerability in mitmproxy, published on 16 Sep 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-2021-39214 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- mitmproxy (PyPI): affected all versions; fixed in 7.0.3\n- mitmproxy (PyPI): affected all versions; fixed in 7.0.3\n- mitmproxy (PyPI): affected all versions; fixed in 7.0.3\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-2021-39214/ (Markdown: https://insights.sbomify.com/CVE-2021-39214/index.md)","id":"CVE-2021-39214","markdown":"https://insights.sbomify.com/CVE-2021-39214/index.md","name":"CVE-2021-39214","record":{"aliases":["DEBIAN-CVE-2021-39214","GHSA-22gh-3r9q-xf38","PYSEC-2021-328","UBUNTU-CVE-2021-39214","openSUSE-SU-2023:0232-1","openSUSE-SU-2023:0233-1"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"SSL/TLS intercepting proxy","requires_auth":"none","summary":"Attackers can smuggle HTTP requests through mitmproxy, bypassing custom access controls and input sanitization implemented in event hooks.","user_interaction":"not_required","vuln_class":"other"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"mitmproxy","vendor":"mitmproxy"}],"cvss":{"score":8.1,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-444","name":"Inconsistent Interpretation of HTTP Requests"}],"description":"mitmproxy is an interactive, SSL/TLS-capable intercepting proxy. In mitmproxy 7.0.2 and below, a malicious client or server is able to perform HTTP request smuggling attacks through mitmproxy. This means that a malicious client/server could smuggle a request/response through mitmproxy as part of another request/response's HTTP message body. While a smuggled request is still captured as part of another request's body, it does not appear in the request list and does not go through the usual mitmproxy event hooks, where users may have implemented custom access control checks or input sanitization. Unless one uses mitmproxy to protect an HTTP/1 service, no action is required. The vulnerability has been fixed in mitmproxy 7.0.3 and above.","ecosystems":["PyPI","SUSE:Package Hub 15 SP4","SUSE:Package Hub 15 SP5","openSUSE:Leap 15.4","openSUSE:Leap 15.5"],"exploits":{"exploitdb":0,"first_seen":"2026-10-08","github_poc":1,"max_poc_stars":0,"metasploit":0,"nuclei":0,"refs":[{"date":"2026-10-08T14:43:10Z","kind":"github_poc","ref":"https://github.com/CyberCTF/secdevlabs-golden-hat","stars":0,"title":"secDevLabs Golden Hat Society: mitmproxy 5.3.0 request smuggling, CVE-2021-39214 (OWASP A06), run with Isoloom"}],"tier":"poc_unverified"},"has_fix":true,"headline":"Lacking Protection against HTTP Request Smuggling in mitmproxy","id":"CVE-2021-39214","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"PyPI","product":null,"products":[],"type":"other","year":"2021"},"n_packages":7,"n_references":1,"next":{"headline":"Authentication Bypass: Forged Tokens Allow Access to Arbitrary Rooms","id":"CVE-2021-39215"},"packages":[{"ecosystem":"PyPI","fixed":["7.0.3"],"introduced":["0"],"last_affected":[],"package":"mitmproxy","purl":null,"source":"GHSA-22gh-3r9q-xf38"},{"ecosystem":"PyPI","fixed":["7.0.3"],"introduced":["0"],"last_affected":[],"package":"mitmproxy","purl":"pkg:pypi/mitmproxy","source":"GHSA-22gh-3r9q-xf38"},{"ecosystem":"PyPI","fixed":["7.0.3"],"introduced":["0"],"last_affected":[],"package":"mitmproxy","purl":"pkg:pypi/mitmproxy","source":"PYSEC-2021-328"},{"ecosystem":"SUSE:Package Hub 15 SP4","fixed":["3.0.4-bp154.2.3.1"],"introduced":["0"],"last_affected":[],"package":"python-mitmproxy","purl":"pkg:rpm/suse/python-mitmproxy\u0026distro=SUSE%20Package%20Hub%2015%20SP4","source":"openSUSE-SU-2023:0232-1"},{"ecosystem":"SUSE:Package Hub 15 SP5","fixed":["3.0.4-bp155.3.3.1"],"introduced":["0"],"last_affected":[],"package":"python-mitmproxy","purl":"pkg:rpm/suse/python-mitmproxy\u0026distro=SUSE%20Package%20Hub%2015%20SP5","source":"openSUSE-SU-2023:0233-1"},{"ecosystem":"openSUSE:Leap 15.4","fixed":["3.0.4-bp154.2.3.1"],"introduced":["0"],"last_affected":[],"package":"python-mitmproxy","purl":"pkg:rpm/opensuse/python-mitmproxy\u0026distro=openSUSE%20Leap%2015.4","source":"openSUSE-SU-2023:0232-1"},{"ecosystem":"openSUSE:Leap 15.5","fixed":["3.0.4-bp155.3.3.1"],"introduced":["0"],"last_affected":[],"package":"python-mitmproxy","purl":"pkg:rpm/opensuse/python-mitmproxy\u0026distro=openSUSE%20Leap%2015.5","source":"openSUSE-SU-2023:0233-1"}],"prev":{"headline":"IP restriction on GLPI API Bypass with custom header injection","id":"CVE-2021-39213"},"products":["mitmproxy"],"published":"2021-09-16","related":[{"cvss_score":9.8,"headline":"Insufficient Protection against HTTP Request Smuggling in mitmproxy","id":"CVE-2022-24766","kev_date_added":null,"published":"2022-03-21"},{"cvss_score":8.8,"headline":"Mitmweb in mitmproxy allows DNS Rebinding attacks","id":"CVE-2018-14505","kev_date_added":null,"published":"2018-07-22"},{"cvss_score":4.8,"headline":"ProxyAuth Addon LDAP Injection in mitmproxy","id":"CVE-2026-40606","kev_date_added":null,"published":"2026-04-21"}],"sources":[{"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":"PyPA Advisory Database","prefix":"PYSEC"},{"class":"attribution","licence":"CC BY 4.0","name":"SUSE","prefix":"openSUSE"},{"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":"open","licence":"CC0","name":"PoC-in-GitHub"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2024-08-04","vendors":["mitmproxy"]},"summary":"Attackers can smuggle HTTP requests through mitmproxy, bypassing custom access controls and input sanitization implemented in event hooks.","url":"https://insights.sbomify.com/CVE-2021-39214/"}