{"answers":{"affected":"2 open source packages ship an affected version, including OPCFoundation.NetStandard.Opc.Ua.Server. It affects 1 product.","exploited":"There is no known exploitation of CVE-2023-27321 in the wild and no public exploit code.","fix":"Upgrade OPCFoundation.NetStandard.Opc.Ua.Server to 1.4.371.86 or later.","what":"CVE-2023-27321 is a high-severity denial of service vulnerability in OPC Foundation UA .NET Standard, published on 7 May 2024. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2023-27321 and fix it if it is affected.\n\nWhat it is: CVE-2023-27321 is a high-severity denial of service vulnerability in OPC Foundation UA .NET Standard, published on 7 May 2024. 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-2023-27321 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- OPCFoundation.NetStandard.Opc.Ua.Server (NuGet): affected all versions; fixed in 1.4.371.86\n- OPCFoundation.NetStandard.Opc.Ua.Server (NuGet): affected all versions; fixed in 1.4.371.86\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-2023-27321/ (Markdown: https://insights.sbomify.com/CVE-2023-27321/index.md)","id":"CVE-2023-27321","markdown":"https://insights.sbomify.com/CVE-2023-27321/index.md","name":"CVE-2023-27321","record":{"aliases":["GHSA-vpf7-r2fv-75m9"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"OPC UA .NET library","requires_auth":"none","summary":"Remote attackers can cause denial of service in OPC Foundation UA .NET Standard by exhausting server resources via ConditionRefresh requests.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"zdi","cpe":[{"product":"ua-.netstandard","vendor":"opcfoundation"}],"cvss":{"score":7.5,"severity":"high","source":"cna","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.0"},"cwes":[{"id":"CWE-400","name":"Uncontrolled Resource Consumption"}],"description":"OPC Foundation UA .NET Standard ConditionRefresh Resource Exhaustion Denial-of-Service Vulnerability. This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of OPC Foundation UA .NET Standard. Authentication is not required to exploit this vulnerability.\n\nThe specific flaw exists within the handling of OPC UA ConditionRefresh requests. By sending a large number of requests, an attacker can consume all available resources on the server. An attacker can leverage this vulnerability to create a denial-of-service condition on the system. Was ZDI-CAN-20505.","ecosystems":["NuGet"],"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":"OPC Foundation UA .NET Standard ConditionRefresh Resource Exhaustion Denial-of-Service Vulnerability","id":"CVE-2023-27321","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"NuGet","product":null,"products":[],"type":"denial_of_service","year":"2023"},"n_packages":2,"n_references":2,"next":{"headline":"Parallels Desktop Service Improper Initialization Local Privilege Escalation Vulnerability","id":"CVE-2023-27322"},"packages":[{"ecosystem":"NuGet","fixed":["1.4.371.86"],"introduced":["0"],"last_affected":[],"package":"OPCFoundation.NetStandard.Opc.Ua.Server","purl":null,"source":"GHSA-vpf7-r2fv-75m9"},{"ecosystem":"NuGet","fixed":["1.4.371.86"],"introduced":["0"],"last_affected":[],"package":"OPCFoundation.NetStandard.Opc.Ua.Server","purl":"pkg:nuget/OPCFoundation.NetStandard.Opc.Ua.Server","source":"GHSA-vpf7-r2fv-75m9"}],"prev":{"headline":"Use after free in n/a","id":"CVE-2023-27320"},"products":["UA .NET Standard"],"published":"2024-05-07","related":[{"cvss_score":5.3,"headline":"Exposure of Sensitive Information in OPC UA .NET Standard Reference Server","id":"CVE-2023-31048","kev_date_added":null,"published":"2023-12-12"},{"cvss_score":4.4,"headline":"Improper Certificate Validation in OPCFoundation.NetStandard.Opc.Ua.Core","id":"CVE-2020-29457","kev_date_added":null,"published":"2021-02-16"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"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":"2024-08-02","vendors":["OPC Foundation"]},"summary":"Remote attackers can cause denial of service in OPC Foundation UA .NET Standard by exhausting server resources via ConditionRefresh requests.","url":"https://insights.sbomify.com/CVE-2023-27321/"}