{"answers":{"affected":"3 open source packages ship an affected version, including fluentd. It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-41186 in the wild and no public exploit code.","fix":"Upgrade fluentd to 1.14.2 or later.","what":"CVE-2021-41186 is a medium-severity denial of service vulnerability in fluentd, published on 29 Oct 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-2021-41186 and fix it if it is affected.\n\nWhat it is: CVE-2021-41186 is a medium-severity denial of service vulnerability in fluentd, published on 29 Oct 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-2021-41186 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- fluentd (Bitnami): affected from 0.14.14; fixed in 1.14.2\n- fluentd (RubyGems): affected from 0.14.14; fixed in 1.14.2\n- fluentd (RubyGems): affected from 0.14.14; fixed in 1.14.2\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-2021-41186/ (Markdown: https://insights.sbomify.com/CVE-2021-41186/index.md)","id":"CVE-2021-41186","markdown":"https://insights.sbomify.com/CVE-2021-41186/index.md","name":"CVE-2021-41186","record":{"aliases":["BIT-fluentd-2021-41186","GHSA-hwhf-64mh-r662","openSUSE-SU-2024:11795-1","openSUSE-SU-2024:13155-1","openSUSE-SU-2024:14072-1","openSUSE-SU-2025:15115-1","openSUSE-SU-2026:10346-1"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Fluentd log collector","requires_auth":"none","summary":"Attackers can cause a denial of service in Fluentd by sending malformed Apache logs that trigger excessive CPU usage in the parser_apache2 plugin.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"fluentd","vendor":"fluentd"}],"cvss":{"score":5.9,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-400","name":"Uncontrolled Resource Consumption"}],"description":"Fluentd collects events from various data sources and writes them to files to help unify logging infrastructure. The parser_apache2 plugin in Fluentd v0.14.14 to v1.14.1 suffers from a regular expression denial of service (ReDoS) vulnerability. A broken apache log with a certain pattern of string can spend too much time in a regular expression, resulting in the potential for a DoS attack. This issue is patched in version 1.14.2 There are two workarounds available. Either don't use parser_apache2 for parsing logs (which cannot guarantee generated by Apache), or put patched version of parser_apache2.rb into /etc/fluent/plugin directory (or any other directories specified by the environment variable `FLUENT_PLUGIN` or `--plugin` option of fluentd).","ecosystems":["Bitnami","RubyGems","openSUSE:Tumbleweed"],"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":"ReDoS vulnerability in parser_apache2","id":"CVE-2021-41186","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Bitnami","product":null,"products":[],"type":"denial_of_service","year":"2021"},"n_packages":8,"n_references":3,"next":{"headline":"SQL Injection in DHIS2 Tracker API","id":"CVE-2021-41187"},"packages":[{"ecosystem":"Bitnami","fixed":["1.14.2"],"introduced":["0.14.14"],"last_affected":[],"package":"fluentd","purl":"pkg:bitnami/fluentd","source":"BIT-fluentd-2021-41186"},{"ecosystem":"RubyGems","fixed":["1.14.2"],"introduced":["0.14.14"],"last_affected":[],"package":"fluentd","purl":null,"source":"GHSA-hwhf-64mh-r662"},{"ecosystem":"RubyGems","fixed":["1.14.2"],"introduced":["0.14.14"],"last_affected":[],"package":"fluentd","purl":"pkg:gem/fluentd","source":"GHSA-hwhf-64mh-r662"},{"ecosystem":"openSUSE:Tumbleweed","fixed":["1.15.3-1.4"],"introduced":["0"],"last_affected":[],"package":"ruby3.2-rubygem-fluentd","purl":"pkg:rpm/opensuse/ruby3.2-rubygem-fluentd\u0026distro=openSUSE%20Tumbleweed","source":"openSUSE-SU-2024:13155-1"},{"ecosystem":"openSUSE:Tumbleweed","fixed":["1.14.4-1.1"],"introduced":["0"],"last_affected":[],"package":"rubygem-fluentd","purl":"pkg:rpm/opensuse/rubygem-fluentd\u0026distro=openSUSE%20Tumbleweed","source":"openSUSE-SU-2024:11795-1"},{"ecosystem":"openSUSE:Tumbleweed","fixed":["1.17.0-1.1"],"introduced":["0"],"last_affected":[],"package":"rubygem-fluentd","purl":"pkg:rpm/opensuse/rubygem-fluentd\u0026distro=openSUSE%20Tumbleweed","source":"openSUSE-SU-2024:14072-1"},{"ecosystem":"openSUSE:Tumbleweed","fixed":["1.17.1-1.3"],"introduced":["0"],"last_affected":[],"package":"rubygem-fluentd","purl":"pkg:rpm/opensuse/rubygem-fluentd\u0026distro=openSUSE%20Tumbleweed","source":"openSUSE-SU-2025:15115-1"},{"ecosystem":"openSUSE:Tumbleweed","fixed":["1.17.1-1.5"],"introduced":["0"],"last_affected":[],"package":"rubygem-fluentd","purl":"pkg:rpm/opensuse/rubygem-fluentd\u0026distro=openSUSE%20Tumbleweed","source":"openSUSE-SU-2026:10346-1"}],"prev":{"headline":"Download file outside intended directory","id":"CVE-2021-41185"},"products":["fluentd"],"published":"2021-10-29","related":[{"cvss_score":9.8,"headline":"Fluentd: Remote Code Execution (RCE) via Arbitrary File Write in `${tag}` Placeholder","id":"CVE-2026-44024","kev_date_added":null,"published":"2026-07-08"},{"cvss_score":9.8,"headline":"Fluentd Escape Sequence Injection Vulnerability","id":"CVE-2017-10906","kev_date_added":null,"published":"2017-12-08"},{"cvss_score":8.8,"headline":"Fluent Fluentd and Fluent-ui use default password","id":"CVE-2020-21514","kev_date_added":null,"published":"2023-04-04"},{"cvss_score":7.5,"headline":"Fluentd: Exposure of Sensitive Information via Monitor Agent API","id":"CVE-2026-44025","kev_date_added":null,"published":"2026-07-08"},{"cvss_score":7.5,"headline":"Fluentd: Denial of Service (DoS) via Gzip Decompression Bomb in `in_http` and `in_forward`","id":"CVE-2026-44160","kev_date_added":null,"published":"2026-07-08"},{"cvss_score":7.2,"headline":"Fluentd: Server-Side Request Forgery (SSRF) via Placeholder Expansion in `out_http`","id":"CVE-2026-44161","kev_date_added":null,"published":"2026-07-08"}],"sources":[{"class":"attribution","licence":"Apache-2.0","name":"Bitnami","prefix":"BIT"},{"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":"SUSE","prefix":"openSUSE"},{"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":"2024-08-04","vendors":["fluent"]},"summary":"Attackers can cause a denial of service in Fluentd by sending malformed Apache logs that trigger excessive CPU usage in the parser_apache2 plugin.","url":"https://insights.sbomify.com/CVE-2021-41186/"}