{"answers":{"affected":"3 open source packages ship an affected version, including matrix-synapse. It affects 2 products.","exploited":"There is no known exploitation of CVE-2021-21392 in the wild and no public exploit code.","fix":"Upgrade matrix-synapse to a fixed version for your release line: 1.28.0 or 1.28.0rc1.","what":"CVE-2021-21392 is a medium-severity server-side request forgery vulnerability in Fedoraproject Fedora, published on 12 Apr 2021. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2021-21392 and fix it if it is affected.\n\nWhat it is: CVE-2021-21392 is a medium-severity server-side request forgery vulnerability in Fedoraproject Fedora, published on 12 Apr 2021. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2021-21392 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- matrix-synapse (PyPI): affected all versions; fixed in 1.28.0\n- matrix-synapse (PyPI): affected all versions; fixed in 1.28.0rc1\n- matrix-synapse (PyPI): affected all versions; fixed in 1.28.0rc1\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-2021-21392/ (Markdown: https://insights.sbomify.com/CVE-2021-21392/index.md)","id":"CVE-2021-21392","markdown":"https://insights.sbomify.com/CVE-2021-21392/index.md","name":"CVE-2021-21392","record":{"aliases":["GHSA-5wrh-4jwv-5w78","PYSEC-2021-25","UBUNTU-CVE-2021-21392"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["data_read","security_bypass"],"network_reachable":"yes","non_default_config":true,"product_category":"Matrix homeserver","requires_auth":"low_privilege","summary":"Attackers can force the Matrix homeserver to make requests to internal infrastructure on dual-stack networks via transitional IPv6 addresses.","user_interaction":"required","vuln_class":"ssrf"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"fedora","vendor":"fedoraproject"},{"product":"synapse","vendor":"matrix"}],"cvss":{"score":6.3,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:H/A:N","version":"3.1"},"cwes":[{"id":"CWE-601","name":"URL Redirection to Untrusted Site"}],"description":"Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is an ecosystem for open federated Instant Messaging and VoIP. In Synapse before version 1.28.0 requests to user provided domains were not restricted to external IP addresses when transitional IPv6 addresses were used. Outbound requests to federation, identity servers, when calculating the key validity for third-party invite events, sending push notifications, and generating URL previews are affected. This could cause Synapse to make requests to internal infrastructure on dual-stack networks. See referenced GitHub security advisory for details and workarounds.","ecosystems":["PyPI"],"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":"Open redirect via transitional IPv6 addresses on dual-stack networks","id":"CVE-2021-21392","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"PyPI","product":"fedoraproject:fedora","products":["fedoraproject:fedora"],"type":"ssrf","year":"2021"},"n_packages":3,"n_references":4,"next":{"headline":"Denial of service (via resource exhaustion) due to improper input validation on groups/communities endpoints","id":"CVE-2021-21393"},"packages":[{"ecosystem":"PyPI","fixed":["1.28.0"],"introduced":["0"],"last_affected":[],"package":"matrix-synapse","purl":"pkg:pypi/matrix-synapse","source":"PYSEC-2021-25"},{"ecosystem":"PyPI","fixed":["1.28.0rc1"],"introduced":["0"],"last_affected":[],"package":"matrix-synapse","purl":null,"source":"GHSA-5wrh-4jwv-5w78"},{"ecosystem":"PyPI","fixed":["1.28.0rc1"],"introduced":["0"],"last_affected":[],"package":"matrix-synapse","purl":"pkg:pypi/matrix-synapse","source":"GHSA-5wrh-4jwv-5w78"}],"prev":{"headline":"Regular expression Denial of Service in multiple packages","id":"CVE-2021-21391"},"products":["synapse"],"published":"2021-04-12","related":[{"cvss_score":9.8,"headline":"PHP-CGI OS Command Injection","id":"CVE-2024-4577","kev_date_added":"2024-06-12","published":"2024-06-09"},{"cvss_score":9.8,"headline":"Grafana Authentication Bypass","id":"CVE-2021-39226","kev_date_added":"2022-08-25","published":"2021-10-05"},{"cvss_score":9.8,"headline":"VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow","id":"CVE-2019-5544","kev_date_added":"2021-11-03","published":"2019-12-06"},{"cvss_score":9.6,"headline":"Google Chromium V8 Type Confusion","id":"CVE-2024-4947","kev_date_added":"2024-05-20","published":"2024-05-15"},{"cvss_score":9.6,"headline":"Google Chromium Visuals Use-After-Free","id":"CVE-2024-4671","kev_date_added":"2024-05-13","published":"2024-05-09"},{"cvss_score":9.6,"headline":"Google Chromium Mojo Insufficient Data Validation","id":"CVE-2022-3075","kev_date_added":"2022-09-08","published":"2022-09-26"},{"cvss_score":9.6,"headline":"Google Chromium Indexed DB API Use-After-Free","id":"CVE-2021-30633","kev_date_added":"2021-11-03","published":"2021-10-08"}],"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":"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":["matrix-org"]},"summary":"Attackers can force the Matrix homeserver to make requests to internal infrastructure on dual-stack networks via transitional IPv6 addresses.","url":"https://insights.sbomify.com/CVE-2021-21392/"}