{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-0205 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2021-0205 yet. Limit exposure of the affected software until one is available.","what":"CVE-2021-0205 is a medium-severity vulnerability in Juniper Junos, published on 15 Jan 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-2021-0205 and fix it if it is affected.\n\nWhat it is: CVE-2021-0205 is a medium-severity vulnerability in Juniper Junos, published on 15 Jan 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-2021-0205 in the wild and no public exploit code.\n\nAffected product: Juniper Junos. 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-2021-0205/ (Markdown: https://insights.sbomify.com/CVE-2021-0205/index.md)","id":"CVE-2021-0205","markdown":"https://insights.sbomify.com/CVE-2021-0205/index.md","name":"CVE-2021-0205","record":{"aliases":["GHSA-pjq4-grjv-rg5j"],"analysis":{"component_type":"network_device","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":true,"product_category":"Juniper MX router","requires_auth":"none","summary":"Incorrect IPv6 prefix matching in IDS dynamic filters blocks legitimate traffic, causing denial of service on Juniper MX Series devices.","user_interaction":"not_required","vuln_class":"misconfiguration"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"juniper","cpe":[{"product":"junos","vendor":"juniper"}],"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:N/A:L","version":"3.1"},"cwes":[{"id":"CWE-284","name":"Improper Access Control"}],"description":"When the \"Intrusion Detection Service\" (IDS) feature is configured on Juniper Networks MX series with a dynamic firewall filter using IPv6 source or destination prefix, it may incorrectly match the prefix as /32, causing the filter to block unexpected traffic. This issue affects only IPv6 prefixes when used as source and destination. This issue affects MX Series devices using MS-MPC, MS-MIC or MS-SPC3 service cards with IDS service configured. This issue affects: Juniper Networks Junos OS 17.3 versions prior to 17.3R3-S10 on MX Series; 17.4 versions prior to 17.4R3-S3 on MX Series; 18.1 versions prior to 18.1R3-S11 on MX Series; 18.2 versions prior to 18.2R3-S6 on MX Series; 18.3 versions prior to 18.3R3-S4 on MX Series; 18.4 versions prior to 18.4R3-S6 on MX Series; 19.1 versions prior to 19.1R2-S2, 19.1R3-S3 on MX Series; 19.2 versions prior to 19.2R3-S1 on MX Series; 19.3 versions prior to 19.3R2-S5, 19.3R3-S1 on MX Series; 19.4 versions prior to 19.4R3 on MX Series; 20.1 versions prior to 20.1R2 on MX Series; 20.2 versions prior to 20.2R2 on MX Series;","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":"Junos OS: MX Series: Dynamic filter fails to match IPv6 prefix","id":"CVE-2021-0205","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"juniper:junos","products":["juniper:junos"],"type":"misconfiguration","year":"2021"},"n_packages":0,"n_references":1,"next":{"headline":"Junos OS: NFX Series, SRX Series: PFE may crash upon receipt of specific packet when SSL Proxy is configured.","id":"CVE-2021-0206"},"packages":[],"prev":{"headline":"Junos OS: dexp Local Privilege Escalation vulnerabilities in SUID binaries","id":"CVE-2021-0204"},"products":["Junos OS"],"published":"2021-01-15","related":[{"cvss_score":9.8,"headline":"Juniper Junos OS EX Series and SRX Series PHP External Variable Modification","id":"CVE-2023-36845","kev_date_added":"2023-11-13","published":"2023-08-17"},{"cvss_score":8.8,"headline":"Juniper Junos OS Path Traversal","id":"CVE-2020-1631","kev_date_added":"2022-03-25","published":"2020-05-04"},{"cvss_score":6.7,"headline":"Juniper Junos OS Improper Isolation or Compartmentalization","id":"CVE-2025-21590","kev_date_added":"2025-03-13","published":"2025-03-12"},{"cvss_score":5.3,"headline":"Juniper Junos OS SRX Series Missing Authentication for Critical Function","id":"CVE-2023-36851","kev_date_added":"2023-11-13","published":"2023-09-26"},{"cvss_score":5.3,"headline":"Juniper Junos OS EX Series PHP External Variable Modification","id":"CVE-2023-36844","kev_date_added":"2023-11-13","published":"2023-08-17"},{"cvss_score":5.3,"headline":"Juniper Junos OS SRX Series Missing Authentication for Critical Function","id":"CVE-2023-36846","kev_date_added":"2023-11-13","published":"2023-08-17"},{"cvss_score":5.3,"headline":"Juniper Junos OS EX Series Missing Authentication for Critical Function","id":"CVE-2023-36847","kev_date_added":"2023-11-13","published":"2023-08-17"}],"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":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2024-09-16","vendors":["Juniper Networks"]},"summary":"Incorrect IPv6 prefix matching in IDS dynamic filters blocks legitimate traffic, causing denial of service on Juniper MX Series devices.","url":"https://insights.sbomify.com/CVE-2021-0205/"}