{"answers":{"affected":"7 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-2017-18876 in the wild and no public exploit code.","fix":"Upgrade github.com/mattermost/mattermost-server to a fixed version for your release line: 4.1.2-0.20171004201910-6be8113eb60c, 4.2.1-0.20171004194140-6d3cb2ce07fc, 4.3.0 or 4.3.0+incompatible.","what":"CVE-2017-18876 is a medium-severity vulnerability in Mattermost Mattermost Server, published on 19 Jun 2020. An attacker needs administrator access to exploit it, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2017-18876 and fix it if it is affected.\n\nWhat it is: CVE-2017-18876 is a medium-severity vulnerability in Mattermost Mattermost Server, published on 19 Jun 2020. An attacker needs administrator access to exploit it, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2017-18876 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 4.1.2-0.20171004201910-6be8113eb60c\n- github.com/mattermost/mattermost-server (Go): affected all versions; fixed in 4.1.2-0.20171004201910-6be8113eb60c\n- github.com/mattermost/mattermost-server (Go): affected from 4.2.0-rc1.0.20171004154238-fadd9514f6e7; fixed in 4.2.1-0.20171004194140-6d3cb2ce07fc\n- github.com/mattermost/mattermost-server (Go): affected from 4.2.0-rc1.0.20171004154238-fadd9514f6e7; fixed in 4.2.1-0.20171004194140-6d3cb2ce07fc\n- github.com/mattermost/mattermost-server (Go): affected from 4.3.0-rc1; fixed in 4.3.0\n- github.com/mattermost/mattermost-server (Go): affected from 4.3.0-rc1; fixed in 4.3.0\n- github.com/mattermost/mattermost-server (Go): affected from 4.3.0-rc1+incompatible; fixed in 4.3.0+incompatible\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-2017-18876/ (Markdown: https://insights.sbomify.com/CVE-2017-18876/index.md)","id":"CVE-2017-18876","markdown":"https://insights.sbomify.com/CVE-2017-18876/index.md","name":"CVE-2017-18876","record":{"aliases":["GHSA-hjqh-j6rj-gh8q","GO-2025-4187"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["data_read"],"network_reachable":"yes","non_default_config":true,"product_category":"Mattermost Server","requires_auth":"high_privilege","summary":"A System Admin can test for the existence of arbitrary files when local storage is used, leading to information disclosure.","user_interaction":"not_required","vuln_class":"information_disclosure"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"mitre","cpe":[{"product":"mattermost_server","vendor":"mattermost"}],"cvss":{"score":4.9,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N","version":"3.1"},"cwes":[{"id":"CWE-732","name":"Incorrect Permission Assignment for Critical Resource"}],"description":"An issue was discovered in Mattermost Server before 4.3.0, 4.2.1, and 4.1.2 when local storage for files is used. A System Admin can test for the existence of an arbitrary file.","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 is vulnerable to Path Traversal when files are stored locally","id":"CVE-2017-18876","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Go","product":"mattermost:mattermost_server","products":["mattermost:mattermost_server"],"type":"information_disclosure","year":"2017"},"n_packages":7,"n_references":1,"next":{"headline":"Mattermost Server is vulnerable to XSS attacks against an OAuth 2.0 allow/deny page","id":"CVE-2017-18877"},"packages":[{"ecosystem":"Go","fixed":["4.1.2-0.20171004201910-6be8113eb60c"],"introduced":["0"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":null,"source":"GHSA-hjqh-j6rj-gh8q"},{"ecosystem":"Go","fixed":["4.1.2-0.20171004201910-6be8113eb60c"],"introduced":["0"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","source":"GHSA-hjqh-j6rj-gh8q"},{"ecosystem":"Go","fixed":["4.2.1-0.20171004194140-6d3cb2ce07fc"],"introduced":["4.2.0-rc1.0.20171004154238-fadd9514f6e7"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":null,"source":"GHSA-hjqh-j6rj-gh8q"},{"ecosystem":"Go","fixed":["4.2.1-0.20171004194140-6d3cb2ce07fc"],"introduced":["4.2.0-rc1.0.20171004154238-fadd9514f6e7"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","source":"GHSA-hjqh-j6rj-gh8q"},{"ecosystem":"Go","fixed":["4.3.0"],"introduced":["4.3.0-rc1"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":null,"source":"GHSA-hjqh-j6rj-gh8q"},{"ecosystem":"Go","fixed":["4.3.0"],"introduced":["4.3.0-rc1"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","source":"GHSA-hjqh-j6rj-gh8q"},{"ecosystem":"Go","fixed":["4.3.0+incompatible"],"introduced":["4.3.0-rc1+incompatible"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","source":"GO-2025-4187"}],"prev":{"headline":"Mattermost Server does not prevent System Admin from arbitrary file creation","id":"CVE-2017-18875"},"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":"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":"2024-08-05","vendors":["n/a"]},"summary":"A System Admin can test for the existence of arbitrary files when local storage is used, leading to information disclosure.","url":"https://insights.sbomify.com/CVE-2017-18876/"}