{"answers":{"affected":"It affects 1 product.","exploited":"Yes. Attackers have exploited CVE-2021-33766 in the wild since at least 18 Jan 2022.","fix":"No fix has been published for CVE-2021-33766 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 1 Feb 2022.","what":"CVE-2021-33766 is a high-severity 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-2021-33766 and fix it if it is affected.\n\nWhat it is: CVE-2021-33766 is a high-severity 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-2021-33766 in the wild since at least 18 Jan 2022.\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-2021-33766/ (Markdown: https://insights.sbomify.com/CVE-2021-33766/index.md)","id":"CVE-2021-33766","markdown":"https://insights.sbomify.com/CVE-2021-33766/index.md","name":"CVE-2021-33766","record":{"aliases":["GHSA-f9f4-96j3-5mvr"],"analysis":{"component_type":"server_software","fix_type":"patch","impacts":["data_read"],"network_reachable":"yes","non_default_config":false,"product_category":"Microsoft Exchange Server","requires_auth":"none","summary":"An attacker can exploit this vulnerability in Microsoft Exchange Server to disclose sensitive information.","user_interaction":"not_required","vuln_class":"information_disclosure"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"microsoft","cpe":[{"product":"exchange_server","vendor":"microsoft"}],"cvss":{"score":7.3,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:U/RL:O/RC:C","version":"3.1"},"cwes":[],"description":"Microsoft Exchange Server Information Disclosure Vulnerability","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":"2021-08-31","github_poc":2,"max_poc_stars":45,"metasploit":0,"nuclei":1,"refs":[{"date":"2021-08-31T22:03:13Z","kind":"github_poc","ref":"https://github.com/bhdresh/CVE-2021-33766","stars":45,"title":"ProxyToken (CVE-2021-33766) : An Authentication Bypass in Microsoft Exchange Server POC exploit"},{"date":"2021-09-15T09:09:20Z","kind":"github_poc","ref":"https://github.com/demossl/CVE-2021-33766-ProxyToken","stars":10,"title":"CVE-2021-33766-poc"},{"date":null,"kind":"nuclei","ref":"http/cves/2021/CVE-2021-33766.yaml","stars":null,"title":"Microsoft Exchange - Authentication Bypass"}],"tier":"exploited"},"has_fix":null,"headline":"Microsoft Exchange Server Information Disclosure","id":"CVE-2021-33766","indexable":true,"kev":{"dateAdded":"2022-01-18","dueDate":"2022-02-01","knownRansomwareCampaignUse":"Unknown","product":"Exchange Server","requiredAction":"Apply updates per vendor instructions.","vendorProject":"Microsoft","vulnerabilityName":"Microsoft Exchange Server Information Disclosure"},"kind":"cve","links":{"ecosystem":null,"product":"microsoft:exchange_server","products":["microsoft:exchange_server"],"type":"information_disclosure","year":"2021"},"n_packages":0,"n_references":1,"next":{"headline":"Open Enclave SDK Elevation of Privilege Vulnerability","id":"CVE-2021-33767"},"packages":[],"prev":{"headline":"Windows Installer Spoofing Vulnerability","id":"CVE-2021-33765"},"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-2021-34473","kev_date_added":"2021-11-03","published":"2021-07-14"},{"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":"FIRST CVSS licence","name":"CVSS (FIRST)"},{"class":"attribution","licence":"MIT","name":"Nuclei templates"},{"class":"open","licence":"CC0","name":"PoC-in-GitHub"}],"ssvc":{"automatable":"yes","exploitation":"active","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-08-10","vendors":["Microsoft"]},"summary":"An attacker can exploit this vulnerability in Microsoft Exchange Server to disclose sensitive information.","url":"https://insights.sbomify.com/CVE-2021-33766/"}