{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-28703 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2021-28703 is a high-severity vulnerability in Xen Xen, published on 7 Dec 2021. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2021-28703 and fix it if it is affected.\n\nWhat it is: CVE-2021-28703 is a high-severity vulnerability in Xen Xen, published on 7 Dec 2021. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2021-28703 in the wild and no public exploit code.\n\nAffected product: Xen Xen. 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-2021-28703/ (Markdown: https://insights.sbomify.com/CVE-2021-28703/index.md)","id":"CVE-2021-28703","markdown":"https://insights.sbomify.com/CVE-2021-28703/index.md","name":"CVE-2021-28703","record":{"aliases":["ALPINE-CVE-2021-28703","DEBIAN-CVE-2021-28703","GHSA-mj29-93c5-p3pr","UBUNTU-CVE-2021-28703"],"analysis":{"component_type":"operating_system","fix_type":"patch","impacts":["data_read","privilege_escalation"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Xen hypervisor","requires_auth":"low_privilege","summary":"A race condition in Xen allows guests to retain access to deallocated grant table pages, potentially leading to information disclosure or privilege escalation.","user_interaction":"not_required","vuln_class":"race_condition"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"XEN","cpe":[{"product":"xen","vendor":"xen"}],"cvss":{"score":7,"severity":"high","source":"nvd","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[],"description":"grant table v2 status pages may remain accessible after de-allocation (take two) Guest get permitted access to certain Xen-owned pages of memory. The majority of such pages remain allocated / associated with a guest for its entire lifetime. Grant table v2 status pages, however, get de-allocated when a guest switched (back) from v2 to v1. The freeing of such pages requires that the hypervisor know where in the guest these pages were mapped. The hypervisor tracks only one use within guest space, but racing requests from the guest to insert mappings of these pages may result in any of them to become mapped in multiple locations. Upon switching back from v2 to v1, the guest would then retain access to a page that was freed and perhaps re-used for other purposes. This bug was fortuitously fixed by code cleanup in Xen 4.14, and backported to security-supported Xen branches as a prerequisite of the fix for XSA-378.","ecosystems":[],"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":"Race condition in Xen","id":"CVE-2021-28703","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"xen:xen","products":["xen:xen"],"type":"race_condition","year":"2021"},"n_packages":0,"n_references":2,"next":{"headline":"Denial of service in xen","id":"CVE-2021-28704"},"packages":[],"prev":{"headline":"Use after free in xen","id":"CVE-2021-28702"},"products":["Xen"],"published":"2021-12-07","related":[{"cvss_score":10,"headline":"Privilege escalation in n/a","id":"CVE-2017-10912","kev_date_added":null,"published":"2017-07-05"},{"cvss_score":10,"headline":"Memory corruption in n/a","id":"CVE-2017-10918","kev_date_added":null,"published":"2017-07-05"},{"cvss_score":10,"headline":"Memory corruption in n/a","id":"CVE-2017-10920","kev_date_added":null,"published":"2017-07-05"},{"cvss_score":10,"headline":"Memory corruption in n/a","id":"CVE-2017-10921","kev_date_added":null,"published":"2017-07-05"},{"cvss_score":9.8,"headline":"Mutiple vulnerabilities in the Viridian interface","id":"CVE-2025-27466","kev_date_added":null,"published":"2025-09-11"},{"cvss_score":9.8,"headline":"Mutiple vulnerabilities in the Viridian interface","id":"CVE-2025-58142","kev_date_added":null,"published":"2025-09-11"},{"cvss_score":9.8,"headline":"Mutiple vulnerabilities in the Viridian interface","id":"CVE-2025-58143","kev_date_added":null,"published":"2025-09-11"}],"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":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2024-08-03","vendors":["Xen Project"]},"summary":"A race condition in Xen allows guests to retain access to deallocated grant table pages, potentially leading to information disclosure or privilege escalation.","url":"https://insights.sbomify.com/CVE-2021-28703/"}