{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-34767 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2021-34767 yet. Limit exposure of the affected software until one is available.","what":"CVE-2021-34767 is a high-severity denial of service vulnerability in Cisco Ios Xe, published on 23 Sep 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-2021-34767 and fix it if it is affected.\n\nWhat it is: CVE-2021-34767 is a high-severity denial of service vulnerability in Cisco Ios Xe, published on 23 Sep 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-2021-34767 in the wild and no public exploit code.\n\nAffected product: Cisco Ios Xe. 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-2021-34767/ (Markdown: https://insights.sbomify.com/CVE-2021-34767/index.md)","id":"CVE-2021-34767","markdown":"https://insights.sbomify.com/CVE-2021-34767/index.md","name":"CVE-2021-34767","record":{"aliases":["GHSA-xwvm-8x4q-gmr9"],"analysis":{"component_type":"network_device","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Cisco wireless controller","requires_auth":"none","summary":"An unauthenticated adjacent attacker can cause a Layer 2 loop and denial of service in a VLAN by sending crafted IPv6 packets to Cisco Catalyst wireless controllers.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"cisco","cpe":[{"product":"ios_xe","vendor":"cisco"}],"cvss":{"score":7.4,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-670","name":"Always-Incorrect Control Flow Implementation"}],"description":"A vulnerability in IPv6 traffic processing of Cisco IOS XE Wireless Controller Software for Cisco Catalyst 9000 Family Wireless Controllers could allow an unauthenticated, adjacent attacker to cause a Layer 2 (L2) loop in a configured VLAN, resulting in a denial of service (DoS) condition for that VLAN. The vulnerability is due to a logic error when processing specific link-local IPv6 traffic. An attacker could exploit this vulnerability by sending a crafted IPv6 packet that would flow inbound through the wired interface of an affected device. A successful exploit could allow the attacker to cause traffic drops in the affected VLAN, thus triggering the DoS condition.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":"2022-12-20","github_poc":1,"max_poc_stars":0,"metasploit":0,"nuclei":0,"refs":[{"date":"2022-12-20T18:53:00Z","kind":"github_poc","ref":"https://github.com/lukejenkins/CVE-2021-34767","stars":0,"title":"Cisco IOS XE Software for Catalyst 9800 Series Wireless Controllers IPv6 Denial of Service Vulnerability"}],"tier":"poc_unverified"},"has_fix":null,"headline":"Cisco IOS XE Software for Catalyst 9800 Series Wireless Controllers IPv6 Denial of Service Vulnerability","id":"CVE-2021-34767","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"cisco:ios_xe","products":["cisco:ios_xe"],"type":"denial_of_service","year":"2021"},"n_packages":0,"n_references":1,"next":{"headline":"Cisco IOS XE Software for Catalyst 9000 Family Wireless Controllers CAPWAP Denial of Service Vulnerabilities","id":"CVE-2021-34768"},"packages":[],"prev":{"headline":"Cisco Smart Software Manager Privilege Escalation Vulnerability","id":"CVE-2021-34766"},"products":["Cisco IOS XE Software"],"published":"2021-09-23","related":[{"cvss_score":10,"headline":"Cisco IOS XE Web UI Privilege Escalation","id":"CVE-2023-20198","kev_date_added":"2023-10-16","published":"2023-10-16"},{"cvss_score":9.8,"headline":"Cisco IOS Software and Cisco IOS XE Software Quality of Service Remote Code Execution","id":"CVE-2018-0151","kev_date_added":"2022-03-03","published":"2018-03-28"},{"cvss_score":7.2,"headline":"Cisco IOS XE Web UI Command Injection","id":"CVE-2023-20273","kev_date_added":"2023-10-23","published":"2023-10-24"},{"cvss_score":10,"headline":"Hardcoded credentials in Cisco IOS XE Software","id":"CVE-2025-20188","kev_date_added":null,"published":"2025-05-07"},{"cvss_score":10,"headline":"Cisco IOS XE Software for Catalyst 9000 Family Wireless Controllers CAPWAP Remote Code Execution Vulnerability","id":"CVE-2021-34770","kev_date_added":null,"published":"2021-09-23"},{"cvss_score":10,"headline":"Cisco REST API Container for IOS XE Software Authentication Bypass Vulnerability","id":"CVE-2019-12643","kev_date_added":null,"published":"2019-08-28"},{"cvss_score":9.8,"headline":"Cisco IOS XE Software Security Hardening Release","id":"CVE-2026-20272","kev_date_added":null,"published":"2026-08-05"}],"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":"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":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2024-11-07","vendors":["Cisco"]},"summary":"An unauthenticated adjacent attacker can cause a Layer 2 loop and denial of service in a VLAN by sending crafted IPv6 packets to Cisco Catalyst wireless controllers.","url":"https://insights.sbomify.com/CVE-2021-34767/"}