{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-1591 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2021-1591 yet. Limit exposure of the affected software until one is available.","what":"CVE-2021-1591 is a medium-severity vulnerability in Cisco Nx-Os, published on 25 Aug 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-2021-1591 and fix it if it is affected.\n\nWhat it is: CVE-2021-1591 is a medium-severity vulnerability in Cisco Nx-Os, published on 25 Aug 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2021-1591 in the wild and no public exploit code.\n\nAffected product: Cisco Nx-Os. 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-2021-1591/ (Markdown: https://insights.sbomify.com/CVE-2021-1591/index.md)","id":"CVE-2021-1591","markdown":"https://insights.sbomify.com/CVE-2021-1591/index.md","name":"CVE-2021-1591","record":{"aliases":["GHSA-7mcq-4g86-cgx3"],"analysis":{"component_type":"network_device","fix_type":"patch","impacts":["security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"Cisco Nexus Switch","requires_auth":"none","summary":"Unauthenticated remote attackers can bypass Access Control List rules on Cisco Nexus 9500 switches due to resource oversubscription in EtherChannel logic.","user_interaction":"not_required","vuln_class":"security_feature_bypass"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"cisco","cpe":[{"product":"nx-os","vendor":"cisco"}],"cvss":{"score":5.8,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N","version":"3.1"},"cwes":[{"id":"CWE-284","name":"Improper Access Control"}],"description":"A vulnerability in the EtherChannel port subscription logic of Cisco Nexus 9500 Series Switches could allow an unauthenticated, remote attacker to bypass access control list (ACL) rules that are configured on an affected device. This vulnerability is due to oversubscription of resources that occurs when applying ACLs to port channel interfaces. An attacker could exploit this vulnerability by attempting to access network resources that are protected by the ACL. A successful exploit could allow the attacker to access network resources that would be protected by the ACL that was applied on the port channel interface.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":null,"headline":"Cisco Nexus 9500 Series Switches Access Control List Bypass Vulnerability","id":"CVE-2021-1591","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"cisco:nx-os","products":["cisco:nx-os"],"type":"security_feature_bypass","year":"2021"},"n_packages":0,"n_references":1,"next":{"headline":"Cisco UCS Manager Software SSH Sessions Denial of Service Vulnerability","id":"CVE-2021-1592"},"packages":[],"prev":{"headline":"Cisco NX-OS Software system login block-for Denial of Service Vulnerability","id":"CVE-2021-1590"},"products":["Cisco NX-OS Software"],"published":"2021-08-25","related":[{"cvss_score":6,"headline":"Cisco NX-OS Command Injection","id":"CVE-2024-20399","kev_date_added":"2024-07-02","published":"2024-07-01"},{"cvss_score":9.8,"headline":"Cisco NX-OS Software Unauthenticated Arbitrary File Actions Vulnerability","id":"CVE-2021-1361","kev_date_added":null,"published":"2021-02-24"},{"cvss_score":9.8,"headline":"Memory corruption in Cisco NX-OS unknown","id":"CVE-2018-0301","kev_date_added":null,"published":"2018-06-20"},{"cvss_score":9.8,"headline":"Memory corruption in n/a","id":"CVE-2016-1453","kev_date_added":null,"published":"2016-10-06"},{"cvss_score":9.8,"headline":"Hardcoded credentials in n/a","id":"CVE-2016-1341","kev_date_added":null,"published":"2016-02-24"},{"cvss_score":8.8,"headline":"Cisco NX-OS Software NX-API Command Injection Vulnerability","id":"CVE-2022-20650","kev_date_added":null,"published":"2022-02-23"},{"cvss_score":8.8,"headline":"Cisco NX-OS Software Data Management Engine Remote Code Execution Vulnerability","id":"CVE-2020-3415","kev_date_added":null,"published":"2020-08-27"}],"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)"}],"ssvc":{"automatable":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2024-11-07","vendors":["Cisco"]},"summary":"Unauthenticated remote attackers can bypass Access Control List rules on Cisco Nexus 9500 switches due to resource oversubscription in EtherChannel logic.","url":"https://insights.sbomify.com/CVE-2021-1591/"}