{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2025-21594 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2025-21594 yet. Limit exposure of the affected software until one is available.","what":"CVE-2025-21594 is a high-severity denial of service vulnerability in Juniper Junos, published on 9 Apr 2025. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2025-21594 and fix it if it is affected.\n\nWhat it is: CVE-2025-21594 is a high-severity denial of service vulnerability in Juniper Junos, published on 9 Apr 2025. 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-2025-21594 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-2025-21594/ (Markdown: https://insights.sbomify.com/CVE-2025-21594/index.md)","id":"CVE-2025-21594","markdown":"https://insights.sbomify.com/CVE-2025-21594/index.md","name":"CVE-2025-21594","record":{"aliases":["GHSA-393v-j9q3-p63r"],"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":"Crafted IPv6 traffic in DS-Lite/NAT scenarios blocks ports, causing denial of service on Juniper MX Series routers.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"juniper","cpe":[{"product":"junos","vendor":"juniper"}],"cvss":{"score":8.7,"severity":"high","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/R:U","version":"4.0"},"cwes":[{"id":"CWE-754","name":"Improper Check for Unusual or Exceptional Conditions"}],"description":"An Improper Check for Unusual or Exceptional Conditions vulnerability in the pfe (packet forwarding engine) of Juniper Networks Junos OS on MX Series causes a port within a pool to be blocked leading to Denial of Service (DoS).\n\nIn a DS-Lite (Dual-Stack Lite) and NAT (Network Address Translation) scenario, when crafted IPv6 traffic is received and prefix-length is set to 56, the ports assigned to the user will not be freed.  Eventually, users cannot establish new connections. Affected FPC/PIC need to be manually restarted to recover.\nFollowing is the command to identify the issue: \n\n    user@host\u003e show services nat source port-block \n    Host_IP                       External_IP                    Port_Block      Ports_Used/        Block_State/\n                                                               Range             Ports_Total        Left_Time(s)\n    2001::                        x.x.x.x                     58880-59391     256/256*1         Active/-        \u003e\u003e\u003e\u003e\u003e\u003e\u003e\u003eport still usedThis issue affects Junos OS on MX Series: \n\n  *  from 21.2 before 21.2R3-S8, \n  *  from 21.4 before 21.4R3-S7, \n  *  from 22.1 before 22.1R3-S6, \n  *  from 22.2 before 22.2R3-S4, \n  *  from 22.3 before 22.3R3-S3, \n  *  from 22.4 before 22.4R3-S2, \n  *  from 23.2 before 23.2R2-S1, \n  *  from 23.4 before 23.4R1-S2, 23.4R2.\n\nThis issue does not affect versions before 20.2R1.","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: In DS-lite and NAT scenario receipt of crafted IPv6 traffic causes port block","id":"CVE-2025-21594","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"juniper:junos","products":["juniper:junos"],"type":"denial_of_service","year":"2025"},"n_packages":0,"n_references":1,"next":{"headline":"Junos OS and Junos OS Evolved: In an EVPN-VXLAN scenario specific ARP or NDP packets cause FPC to crash","id":"CVE-2025-21595"},"packages":[],"prev":{"headline":"Denial of service in Junos OS","id":"CVE-2025-21593"},"products":["Junos OS"],"published":"2025-04-09","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":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2025-04-10","vendors":["Juniper Networks"]},"summary":"Crafted IPv6 traffic in DS-Lite/NAT scenarios blocks ports, causing denial of service on Juniper MX Series routers.","url":"https://insights.sbomify.com/CVE-2025-21594/"}