{"answers":{"affected":"9 open source packages ship an affected version, including github.com/mattermost/mattermost-server. It affects 1 product.","exploited":"There is no known exploitation of CVE-2017-18871 in the wild and no public exploit code.","fix":"Upgrade github.com/mattermost/mattermost-server to a fixed version for your release line: 4.2.2+incompatible, 4.3.4+incompatible, 4.4.5+incompatible or 4.5.0+incompatible.","what":"CVE-2017-18871 is a high-severity denial of service vulnerability in Mattermost Mattermost Server, published on 19 Jun 2020. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2017-18871 and fix it if it is affected.\n\nWhat it is: CVE-2017-18871 is a high-severity denial of service vulnerability in Mattermost Mattermost Server, published on 19 Jun 2020. 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-2017-18871 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- github.com/mattermost/mattermost-server (Go): affected all versions; fixed in 4.2.2+incompatible, 4.3.4+incompatible, 4.4.5+incompatible, 4.5.0+incompatible\n- github.com/mattermost/mattermost-server (Go): affected all versions; fixed in 4.2.2\n- github.com/mattermost/mattermost-server (Go): affected all versions; fixed in 4.2.2\n- github.com/mattermost/mattermost-server (Go): affected from 4.3.0-rc1; fixed in 4.3.4\n- github.com/mattermost/mattermost-server (Go): affected from 4.3.0-rc1; fixed in 4.3.4\n- github.com/mattermost/mattermost-server (Go): affected from 4.4.0-rc1; fixed in 4.4.5\n- github.com/mattermost/mattermost-server (Go): affected from 4.4.0-rc1; fixed in 4.4.5\n- github.com/mattermost/mattermost-server (Go): affected from 4.5.0-rc1; fixed in 4.5.0\n- github.com/mattermost/mattermost-server (Go): affected from 4.5.0-rc1; fixed in 4.5.0\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-2017-18871/ (Markdown: https://insights.sbomify.com/CVE-2017-18871/index.md)","id":"CVE-2017-18871","markdown":"https://insights.sbomify.com/CVE-2017-18871/index.md","name":"CVE-2017-18871","record":{"aliases":["GHSA-jc6w-8r7f-vmp5","GO-2025-4184"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Mattermost Server","requires_auth":"none","summary":"Attackers can crash the Mattermost Server application by sending a specific input containing an @ character before a JavaScript field name.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"mitre","cpe":[{"product":"mattermost_server","vendor":"mattermost"}],"cvss":{"score":7.5,"severity":"high","source":"nvd","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[],"description":"An issue was discovered in Mattermost Server before 4.5.0, 4.4.5, 4.3.4, and 4.2.2. It allows attackers to cause a denial of service (application crash) via an @ character before a JavaScript field name.","ecosystems":["Go"],"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":"Mattermost Server vulnerable to Denial of Service through `@` character prefix inserted into JavaScript field names","id":"CVE-2017-18871","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Go","product":"mattermost:mattermost_server","products":["mattermost:mattermost_server"],"type":"denial_of_service","year":"2017"},"n_packages":9,"n_references":1,"next":{"headline":"Mattermost Server's OAuth 2.0 service is vulnerable to attack through Missing Authorization","id":"CVE-2017-18872"},"packages":[{"ecosystem":"Go","fixed":["4.2.2+incompatible","4.3.4+incompatible","4.4.5+incompatible","4.5.0+incompatible"],"introduced":["0","4.3.0-rc1+incompatible","4.4.0-rc1+incompatible","4.5.0-rc1+incompatible"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","source":"GO-2025-4184"},{"ecosystem":"Go","fixed":["4.2.2"],"introduced":["0"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":null,"source":"GHSA-jc6w-8r7f-vmp5"},{"ecosystem":"Go","fixed":["4.2.2"],"introduced":["0"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","source":"GHSA-jc6w-8r7f-vmp5"},{"ecosystem":"Go","fixed":["4.3.4"],"introduced":["4.3.0-rc1"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":null,"source":"GHSA-jc6w-8r7f-vmp5"},{"ecosystem":"Go","fixed":["4.3.4"],"introduced":["4.3.0-rc1"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","source":"GHSA-jc6w-8r7f-vmp5"},{"ecosystem":"Go","fixed":["4.4.5"],"introduced":["4.4.0-rc1"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":null,"source":"GHSA-jc6w-8r7f-vmp5"},{"ecosystem":"Go","fixed":["4.4.5"],"introduced":["4.4.0-rc1"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","source":"GHSA-jc6w-8r7f-vmp5"},{"ecosystem":"Go","fixed":["4.5.0"],"introduced":["4.5.0-rc1"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":null,"source":"GHSA-jc6w-8r7f-vmp5"},{"ecosystem":"Go","fixed":["4.5.0"],"introduced":["4.5.0-rc1"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","source":"GHSA-jc6w-8r7f-vmp5"}],"prev":{"headline":"Missing authorization in n/a","id":"CVE-2017-18870"},"products":["n/a"],"published":"2020-06-19","related":[{"cvss_score":9.9,"headline":"Account takeover on OAuth/OpenID-enabled servers","id":"CVE-2025-12419","kev_date_added":null,"published":"2025-11-27"},{"cvss_score":9.9,"headline":"Account Takeover via Code Exchange Endpoint","id":"CVE-2025-12421","kev_date_added":null,"published":"2025-11-27"},{"cvss_score":9.9,"headline":"Path Traversal Leading to RCE by Any Authenticated Mattermost User","id":"CVE-2025-4981","kev_date_added":null,"published":"2025-06-20"},{"cvss_score":9.9,"headline":"Arbitrary file read via block duplication in Mattermost Boards","id":"CVE-2025-20051","kev_date_added":null,"published":"2025-02-24"},{"cvss_score":9.9,"headline":"Arbitrary file read in Mattermost Boards via import \u0026 export board archive","id":"CVE-2025-25279","kev_date_added":null,"published":"2025-02-24"},{"cvss_score":9.8,"headline":"Mattermost Server: Insufficient Password-Reset Link Invalidation","id":"CVE-2016-11074","kev_date_added":null,"published":"2020-06-19"},{"cvss_score":9.8,"headline":"Mattermost Server allows attackers to gain privileges by accessing unintended API endpoints with users' credentials","id":"CVE-2017-18885","kev_date_added":null,"published":"2020-06-19"}],"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":"CC BY 4.0","name":"Go Vulnerability Database","prefix":"GO"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2024-08-05","vendors":["n/a"]},"summary":"Attackers can crash the Mattermost Server application by sending a specific input containing an @ character before a JavaScript field name.","url":"https://insights.sbomify.com/CVE-2017-18871/"}