{"answers":{"affected":"It affects 2 products.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2018-18955 exists.","fix":"Apply the vendor's patch.","what":"CVE-2018-18955 is a high-severity vulnerability in Canonical Ubuntu Linux, published on 16 Nov 2018. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2018-18955 and fix it if it is affected.\n\nWhat it is: CVE-2018-18955 is a high-severity vulnerability in Canonical Ubuntu Linux, published on 16 Nov 2018. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2018-18955 exists.\n\nAffected product: Canonical Ubuntu Linux. 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-2018-18955/ (Markdown: https://insights.sbomify.com/CVE-2018-18955/index.md)","id":"CVE-2018-18955","markdown":"https://insights.sbomify.com/CVE-2018-18955/index.md","name":"CVE-2018-18955","record":{"aliases":["DEBIAN-CVE-2018-18955","GHSA-c6xj-3c77-g5rg","UBUNTU-CVE-2018-18955"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["privilege_escalation","data_read"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A local attacker with CAP_SYS_ADMIN in a user namespace can bypass access controls to read sensitive files like /etc/shadow due to mishandled ID transformations.","user_interaction":"not_required","vuln_class":"privilege_escalation"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"mitre","cpe":[{"product":"ubuntu_linux","vendor":"canonical"},{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":7,"severity":"high","source":"nvd","vector":"CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.0"},"cwes":[{"id":"CWE-863","name":"Incorrect Authorization"}],"description":"In the Linux kernel 4.15.x through 4.19.x before 4.19.2, map_write() in kernel/user_namespace.c allows privilege escalation because it mishandles nested user namespaces with more than 5 UID or GID ranges. A user who has CAP_SYS_ADMIN in an affected user namespace can bypass access controls on resources outside the namespace, as demonstrated by reading /etc/shadow. This occurs because an ID transformation takes place properly for the namespaced-to-kernel direction but not for the kernel-to-namespaced direction.","ecosystems":[],"exploits":{"exploitdb":7,"first_seen":"2018-11-15","github_poc":2,"max_poc_stars":25,"metasploit":1,"nuclei":0,"refs":[{"date":"2022-01-19T14:47:47Z","kind":"github_poc","ref":"https://github.com/scheatkode/CVE-2018-18955","stars":25,"title":"💀 Linux local root exploit for CVE-2018-18955"},{"date":"2018-11-15","kind":"metasploit","ref":"exploit/linux/local/nested_namespace_idmap_limit_priv_esc","stars":null,"title":"Linux Nested User Namespace idmap Limit Local Privilege Escalation"},{"date":"2018-11-16","kind":"exploitdb","ref":"45886","stars":null,"title":"Linux - Broken uid/gid Mapping for Nested User Namespaces"},{"date":"2018-11-21","kind":"exploitdb","ref":"47164","stars":null,"title":"Linux Kernel 4.15.x \u003c 4.19.2 - 'map_write() CAP_SYS_ADMIN' Local Privilege Escalation (cron Method)"},{"date":"2018-11-21","kind":"exploitdb","ref":"47166","stars":null,"title":"Linux Kernel 4.15.x \u003c 4.19.2 - 'map_write() CAP_SYS_ADMIN' Local Privilege Escalation (ldpreload Method)"},{"date":"2018-11-29","kind":"exploitdb","ref":"45915","stars":null,"title":"Linux - Nested User Namespace idmap Limit Local Privilege Escalation (Metasploit)"},{"date":"2018-11-29","kind":"exploitdb","ref":"45915","stars":null,"title":"Linux - Nested User Namespace idmap Limit Local Privilege Escalation (Metasploit)"},{"date":"2019-01-04","kind":"exploitdb","ref":"47165","stars":null,"title":"Linux Kernel 4.15.x \u003c 4.19.2 - 'map_write() CAP_SYS_ADMIN' Local Privilege Escalation (dbus Method)"}],"tier":"weaponised"},"has_fix":true,"headline":"Privilege escalation in n/a","id":"CVE-2018-18955","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"canonical:ubuntu_linux","products":["canonical:ubuntu_linux","linux:linux_kernel"],"type":"privilege_escalation","year":"2018"},"n_packages":0,"n_references":15,"next":{"headline":"Denial of service in n/a","id":"CVE-2018-18956"},"packages":[],"prev":{"headline":"Memory corruption in n/a","id":"CVE-2018-18954"},"products":["n/a"],"published":"2018-11-16","related":[{"cvss_score":9.8,"headline":"SaltStack Salt Authentication Bypass","id":"CVE-2020-11651","kev_date_added":"2021-11-03","published":"2020-04-30"},{"cvss_score":9.8,"headline":"OpenSMTPD Remote Code Execution","id":"CVE-2020-7247","kev_date_added":"2022-03-25","published":"2020-01-29"},{"cvss_score":9.8,"headline":"Exim Out-of-bounds Write","id":"CVE-2019-16928","kev_date_added":"2022-03-03","published":"2019-09-27"},{"cvss_score":9.8,"headline":"Exim Buffer Overflow","id":"CVE-2018-6789","kev_date_added":"2021-11-03","published":"2018-02-08"},{"cvss_score":9.8,"headline":"Oracle Java SE and Java SE Embedded Remote Code Execution","id":"CVE-2015-2590","kev_date_added":"2022-03-03","published":"2015-07-16"},{"cvss_score":9.8,"headline":"Oracle JRE Remote Code Execution","id":"CVE-2013-0422","kev_date_added":"2022-05-25","published":"2013-01-10"},{"cvss_score":9.8,"headline":"Oracle Java SE Runtime Environment (JRE) Arbitrary Code Execution","id":"CVE-2011-3544","kev_date_added":"2022-03-03","published":"2011-10-19"}],"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)"},{"class":"attribution","licence":"BSD-3-Clause","name":"Metasploit"},{"class":"attribution","licence":"GPL-2.0-or-later","name":"Exploit-DB"},{"class":"open","licence":"CC0","name":"PoC-in-GitHub"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2024-08-05","vendors":["n/a"]},"summary":"A local attacker with CAP_SYS_ADMIN in a user namespace can bypass access controls to read sensitive files like /etc/shadow due to mishandled ID transformations.","url":"https://insights.sbomify.com/CVE-2018-18955/"}