Published: 16/11/2018 Updated: 24/08/2020

CVSS v2 Base Score: 4.4 | Impact Score: 6.4 | Exploitability Score: 3.4

CVSS v3 Base Score: 7 | Impact Score: 5.9 | Exploitability Score: 1

VMScore: 467

Vector: AV:L/AC:M/Au:N/C:P/I:P/A:P

In the Linux kernel 4.15.x up to and including 4.19.x prior to 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.

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linux linux kernel
canonical ubuntu linux 16.04
canonical ubuntu linux 18.10
canonical ubuntu linux 18.04

Several security issues were fixed in the Linux kernel ...

A flaw was found in the Linux kernel where map_write() in kernel/user_namespacec allows privilege escalation as it mishandles nested user namespaces with more than 5 UID or GID ranges An unprivileged user with CAP_SYS_ADMIN in an affected user namespace can bypass access controls on resources outside the namespace This is possible because a user ...

This Metasploit module exploits a vulnerability in Linux kernels 4150 to 41818, and 4190 to 4191, where broken uid/gid mappings between nested user namespaces and kernel uid/gid mappings allow elevation to root (CVE-2018-18955) The target system must have unprivileged user namespaces enabled and the newuidmap and newgidmap helpers installe ...

#!/bin/sh # # EDB Note: Download ~ githubcom/offensive-security/exploitdb-bin-sploits/raw/master/bin-sploits/47164zip # # wrapper for Jann Horn's exploit for CVE-2018-18955 # uses crontab technique # --- # test@linux-mint-19-2:~/kernel-exploits/CVE-2018-18955$ /exploitcronsh # [*] Compiling # [*] Writing payload to /tmp/payload # ...

commit 6397fac4915a ("userns: bump idmap limits to 340") increases the number of possible uid/gid mappings that a namespace can have from 5 to 340 This is implemented by switching to a different data structure if the number of mappings exceeds 5: Instead of linear search over an unsorted array of struct uid_gid_extent, binary search over a sorted ...

#!/bin/sh # # EDB Note: Download ~ githubcom/offensive-security/exploitdb-bin-sploits/raw/master/bin-sploits/47166zip # # wrapper for Jann Horn's exploit for CVE-2018-18955 # uses ldsopreload technique # --- # test@linux-mint-19-2:~/kernel-exploits/CVE-2018-18955$ /exploitldpreloadsh # [*] Compiling # [*] Adding libsubuidso to /e ...

#!/bin/sh # # EDB Note: Download ~ githubcom/offensive-security/exploitdb-bin-sploits/raw/master/bin-sploits/47167zip # # wrapper for Jann Horn's exploit for CVE-2018-18955 # uses polkit technique # --- # test@linux-mint-19-2:~/kernel-exploits/CVE-2018-18955$ /exploitpolkitsh # [*] Compiling # [*] Creating /usr/share/polkit-1/action ...

#!/bin/sh # # EDB Note: Download ~ githubcom/offensive-security/exploitdb-bin-sploits/raw/master/bin-sploits/47165zip # # wrapper for Jann Horn's exploit for CVE-2018-18955 # uses dbus service technique # --- # test@linux-mint-19-2:~/kernel-exploits/CVE-2018-18955$ /exploitdbussh # [*] Compiling # [*] Creating /usr/share/dbus-1/syst ...

Compte rendu ctf mordor fait dans le cadre de INF805

By VINAI Florent & BELKACEMI Billal COMPTE RENDU CTF MORDOR UDES MAITRISE CYBER 2023 **Introduction ** Défi #1 : Trouver la porte d’entrée de Mordor 5** **Défi #2 : Intrusion dans Mordor 6** **Défi #3 : Accès à DVWA de Samwise 12** **Défi #4 : Accès au fichier “telnetinfotxt” 14** **Défi

Linux-Kernel-Exploits

Linux-Kernel-Exploits CVE-2018-18955 Detail In the Linux kernel 415x through 419x before 4192, map_write() in kernel/user_namespacec 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 demons

Linux-Kernel-Exploits

Linux-Kernel-Exploits CVE-2018-18955 Detail In the Linux kernel 415x through 419x before 4192, map_write() in kernel/user_namespacec 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 demons

POCs can run in some Linux kernel versions

POC-available POCs can run in some Linux kernel versions CVE-2019-11599 POC运行内核版本：462 运行方式： gcc -o coredump_helper coredump_helperc sudo /set_helpersh gcc -o dumpme dumpmec /dumpme 运行结果：运行poc 通过dmesg查看日志 CVE-2019-9213 POC运行内核版本：462 运行方式： gcc -o nullmap nullmapc /nullmap 运行结果： CVE-

💀 Linux local root exploit for CVE-2018-18955

CVE-2018-18955 Linux local root exploit Wrapper for Jann Horn's exploit for CVE-2018-18955, forked from kernel-exploits In the Linux kernel 415x through 419x before 4192, map_write() in kernel/user_namespacec 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 aff

Tryhackme box

thelondonbridge THM TheLondonBridge Walkthrough Hello guys this is my very first box in THM hope you guys will enjoy it, There are mainly 4 stages in this box: *) Scanning *) Enumeration *) Gaining access *) Privilege escalation **) Scan the ip using rustscan: rustscan We found 3 open ports SSH HTTP 44567(further version scan gave us a tcpwrapped service) **) Enumeration We enu

CWE-863 https://github.com/torvalds/linux/commit/d2f007dbe7e4c9583eea6eb04d60001e85c6f1bd https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.2 https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.18.19 https://bugs.chromium.org/p/project-zero/issues/detail?id=1712 http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d2f007dbe7e4c9583eea6eb04d60001e85c6f1bd http://www.securityfocus.com/bid/105941 https://www.exploit-db.com/exploits/45886/https://usn.ubuntu.com/3833-1/https://usn.ubuntu.com/3832-1/https://www.exploit-db.com/exploits/45915/https://usn.ubuntu.com/3836-2/https://usn.ubuntu.com/3836-1/https://usn.ubuntu.com/3835-1/https://support.f5.com/csp/article/K39103040 https://security.netapp.com/advisory/ntap-20190416-0003/https://nvd.nist.gov https://usn.ubuntu.com/3836-1/https://www.exploit-db.com/exploits/47164

CVE-2018-18955

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