{"answers":{"affected":"It affects 1 product.","exploited":"Yes. Attackers have exploited CVE-2021-34473 in the wild since at least 3 Nov 2021, including in ransomware campaigns.","fix":"No fix has been published for CVE-2021-34473 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 17 Nov 2021.","what":"CVE-2021-34473 is a critical server-side request forgery vulnerability in Microsoft Exchange Server, published on 14 Jul 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-2021-34473 and fix it if it is affected.\n\nWhat it is: CVE-2021-34473 is a critical server-side request forgery vulnerability in Microsoft Exchange Server, published on 14 Jul 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: Yes. Attackers have exploited CVE-2021-34473 in the wild since at least 3 Nov 2021, including in ransomware campaigns.\n\nAffected product: Microsoft Exchange Server. No package-level version data is available, so check the vendor advisory linked from the reference page.\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-2021-34473/ (Markdown: https://insights.sbomify.com/CVE-2021-34473/index.md)","id":"CVE-2021-34473","markdown":"https://insights.sbomify.com/CVE-2021-34473/index.md","name":"CVE-2021-34473","record":{"aliases":["GHSA-fgq9-p33g-xcfc"],"analysis":{"component_type":"server_software","fix_type":"patch","impacts":["code_execution"],"network_reachable":"yes","non_default_config":false,"product_category":"Microsoft Exchange Server","requires_auth":"none","summary":"Attackers can exploit a Server-Side Request Forg flaw in Microsoft Exchange Server to achieve remote code execution.","user_interaction":"not_required","vuln_class":"ssrf"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"microsoft","cpe":[{"product":"exchange_server","vendor":"microsoft"}],"cvss":{"score":9.1,"severity":"critical","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C","version":"3.1"},"cwes":[{"id":"CWE-918","name":"Server-Side Request Forgery"}],"description":"Microsoft Exchange Server Remote Code Execution Vulnerability","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":"2021-04-06","github_poc":9,"max_poc_stars":121,"metasploit":1,"nuclei":1,"refs":[{"date":"2021-09-04T15:34:03Z","kind":"github_poc","ref":"https://github.com/horizon3ai/proxyshell","stars":121,"title":"Proof of Concept for CVE-2021-34473, CVE-2021-34523, and CVE-2021-31207"},{"date":"2021-08-10T15:01:02Z","kind":"github_poc","ref":"https://github.com/cyberheartmi9/Proxyshell-Scanner","stars":46,"title":"nuclei scanner for proxyshell ( CVE-2021-34473 )"},{"date":"2022-06-29T12:37:31Z","kind":"github_poc","ref":"https://github.com/kh4sh3i/ProxyShell","stars":43,"title":"CVE-2021-34473 Microsoft Exchange Server Remote Code Execution Vulnerability"},{"date":"2021-08-16T11:27:13Z","kind":"github_poc","ref":"https://github.com/p2-98/CVE-2021-34473","stars":30,"title":"CVE-2021-34473 Microsoft Exchange Server Remote Code Execution Vulnerability"},{"date":"2021-11-22T07:47:09Z","kind":"github_poc","ref":"https://github.com/je6k/CVE-2021-34473-Exchange-ProxyShell","stars":16,"title":"对Exchange Proxyshell 做了二次修改，精确的拆分、实现辅助性安全测试。"},{"date":"2021-08-11T12:20:07Z","kind":"github_poc","ref":"https://github.com/RaouzRouik/CVE-2021-34473-scanner","stars":5,"title":"Scanner for CVE-2021-34473, ProxyShell, A Microsoft Exchange On-premise Vulnerability"},{"date":"2022-11-16T08:22:29Z","kind":"github_poc","ref":"https://github.com/ipsBruno/CVE-2021-34473-NMAP-SCANNER","stars":2,"title":"A massive scanner for CVE-2021-34473 Microsoft Exchange Windows Vulnerability"},{"date":"2021-04-06","kind":"metasploit","ref":"exploit/windows/http/exchange_proxyshell_rce","stars":null,"title":"Microsoft Exchange ProxyShell RCE"}],"tier":"exploited"},"has_fix":null,"headline":"Microsoft Exchange Server Remote Code Execution","id":"CVE-2021-34473","indexable":true,"kev":{"dateAdded":"2021-11-03","dueDate":"2021-11-17","knownRansomwareCampaignUse":"Known","product":"Exchange Server","requiredAction":"Apply updates per vendor instructions.","vendorProject":"Microsoft","vulnerabilityName":"Microsoft Exchange Server Remote Code Execution Vulnerability"},"kind":"cve","links":{"ecosystem":null,"product":"microsoft:exchange_server","products":["microsoft:exchange_server"],"type":"ssrf","year":"2021"},"n_packages":0,"n_references":1,"next":{"headline":"Microsoft Dynamics 365 Business Central Remote Code Execution Vulnerability","id":"CVE-2021-34474"},"packages":[],"prev":{"headline":"Microsoft Defender Elevation of Privilege Vulnerability","id":"CVE-2021-34471"},"products":["Microsoft Exchange Server 2013 Cumulative Update 23","Microsoft Exchange Server 2016 Cumulative Update 19","Microsoft Exchange Server 2016 Cumulative Update 20","Microsoft Exchange Server 2019 Cumulative Update 8","Microsoft Exchange Server 2019 Cumulative Update 9"],"published":"2021-07-14","related":[{"cvss_score":9.8,"headline":"Microsoft Exchange Server Privilege Escalation","id":"CVE-2024-21410","kev_date_added":"2024-02-15","published":"2024-02-13"},{"cvss_score":9.1,"headline":"Microsoft Exchange Server Remote Code Execution","id":"CVE-2021-26855","kev_date_added":"2021-11-03","published":"2021-03-02"},{"cvss_score":9,"headline":"Microsoft Exchange Server Privilege Escalation","id":"CVE-2021-34523","kev_date_added":"2021-11-03","published":"2021-07-14"},{"cvss_score":8.8,"headline":"Microsoft Exchange Server Deserialization of Untrusted Data","id":"CVE-2023-21529","kev_date_added":"2026-04-13","published":"2023-02-14"},{"cvss_score":8.8,"headline":"Microsoft Exchange Server Privilege Escalation","id":"CVE-2022-41080","kev_date_added":"2023-01-10","published":"2022-11-09"},{"cvss_score":8.8,"headline":"Microsoft Exchange Server Server-Side Request Forgery","id":"CVE-2022-41040","kev_date_added":"2022-09-30","published":"2022-10-03"}],"sources":[{"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":"open","licence":"CC0 1.0","name":"CISA KEV"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"},{"class":"attribution","licence":"BSD-3-Clause","name":"Metasploit"},{"class":"open","licence":"CC0","name":"PoC-in-GitHub"}],"ssvc":{"automatable":"yes","exploitation":"active","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-08-10","vendors":["Microsoft"]},"summary":"Attackers can exploit a Server-Side Request Forg flaw in Microsoft Exchange Server to achieve remote code execution.","url":"https://insights.sbomify.com/CVE-2021-34473/"}