Linux - userfaultfd Bypasses tmpfs File Permissions

Linux - userfaultfd Bypasses tmpfs File Permissions Using the userfaultfd API, it is possible to first register a userfaultfd region for any VMA that fulfills vmacanuserfault: It must be an anonymous VMA -vmops==NULL, a hugetlb VMA VMHUGETLB, or a shmem VMA -vmops==shmemvmops. This means that it...

Linux kernel userfaultfd tmpfs file permission bypass vulnerability

Linux kernel is the kernel used by Linux, the open source operating system released by the Linux Foundation in the United States. A security vulnerability exists in the implementation of userfaultfd in versions of Linux kernel prior to 4.19.7, which stems from a program's failure to properly hand...

Linux - 'userfaultfd' Bypasses tmpfs File Permissions

Using the userfaultfd API, it is possible to first register a userfaultfd region for any VMA that fulfills vmacanuserfault: It must be an anonymous VMA -vmops==NULL, a hugetlb VMA VMHUGETLB, or a shmem VMA -vmops==shmemvmops. This means that it is, for example, possible to register userfaulfd...

CVE-2018-18397

The userfaultfd implementation in the Linux kernel before 4.19.7 mishandles access control for certain UFFDIO ioctl calls, as demonstrated by allowing local users to write data into holes in a tmpfs file if the user has read-only access to that file, and that file contains holes, related to...

Design/Logic Flaw

The userfaultfd implementation in the Linux kernel before 4.19.7 mishandles access control for certain UFFDIO ioctl calls, as demonstrated by allowing local users to write data into holes in a tmpfs file if the user has read-only access to that file, and that file contains holes, related to...

DEBIAN-CVE-2018-18397

The userfaultfd implementation in the Linux kernel before 4.19.7 mishandles access control for certain UFFDIO ioctl calls, as demonstrated by allowing local users to write data into holes in a tmpfs file if the user has read-only access to that file, and that file contains holes, related to...

CVE-2018-18397

The vulnerability CVE-2018-18397 affects the Linux kernel prior to 4.19.7, where the userfaultfd implementation mishandles access control for certain UFFDIO ioctls (fs/userfaultfd.c and mm/userfaultfd.c). A local attacker with read permissions on a tmpfs file containing holes could write data int...

CVE-2018-18397

The userfaultfd implementation in the Linux kernel before 4.19.7 mishandles access control for certain UFFDIO ioctl calls, as demonstrated by allowing local users to write data into holes in a tmpfs file if the user has read-only access to that file, and that file contains holes, related to...

CVE-2018-18397

The userfaultfd implementation in the Linux kernel before 4.19.7 mishandles access control for certain UFFDIO ioctl calls, as demonstrated by allowing local users to write data into holes in a tmpfs file if the user has read-only access to that file, and that file contains holes, related to...

CVE-2018-18397

The userfaultfd implementation in the Linux kernel before 4.19.7 mishandles access control for certain UFFDIO ioctl calls, as demonstrated by allowing local users to write data into holes in a tmpfs file if the user has read-only access to that file, and that file contains holes, related to...

CVE-2018-18397: Incorrect Authorization

The userfaultfd implementation in the Linux kernel before 4.19.7 mishandles access control for certain UFFDIO ioctl calls, as demonstrated by allowing local users to write data into holes in a tmpfs file if the user has read-only access to that file, and that file contains holes, related to...

UBUNTU-CVE-2018-18397

The userfaultfd implementation in the Linux kernel before 4.19.7 mishandles access control for certain UFFDIO ioctl calls, as demonstrated by allowing local users to write data into holes in a tmpfs file if the user has read-only access to that file, and that file contains holes, related to...

CVE-2018-18397

The userfaultfd implementation in the Linux kernel before 4.19.7 mishandles access control for certain UFFDIO ioctl calls, as demonstrated by allowing local users to write data into holes in a tmpfs file if the user has read-only access to that file, and that file contains holes, related to...

Linux userfaultfd tmpfs File Permission Bypass

Linux: userfaultfd bypasses tmpfs file permissions CVE-2018-18397 Using the userfaultfd API, it is possible to first register a userfaultfd region for any VMA that fulfills vmacanuserfault: It must be an anonymous VMA -vmops==NULL, a hugetlb VMA VMHUGETLB, or a shmem VMA -vmops==shmemvmops. This...

SUSE SLED12 / SLES12 Security Update : systemd (SUSE-SU-2018:3767-2)

This update for systemd fixes the following issues : Security issues fixed : CVE-2018-15688: A buffer overflow vulnerability in the dhcp6 client of systemd allowed a malicious dhcp6 server to overwrite heap memory in systemd-networkd. bsc1113632 CVE-2018-15686: A vulnerability in unitdeserialize ...

PT-2018-3360

Name of the Vulnerable Software and Affected Versions: Linux kernel versions prior to 4.19.7 Description: The issue exists due to insufficient input validation in the userfaultfd component of the Linux kernel. This could allow an attacker to impact the integrity of protected information. The...

openSUSE Security Update : systemd (openSUSE-2018-1423)

This update for systemd fixes the following issues : Security issues fixed : - CVE-2018-15688: A buffer overflow vulnerability in the dhcp6 client of systemd allowed a malicious dhcp6 server to overwrite heap memory in systemd-networkd. bsc1113632 - CVE-2018-15686: A vulnerability in...

SUSE SLED12 / SLES12 Security Update : systemd (SUSE-SU-2018:3767-1)

This update for systemd fixes the following issues : Security issues fixed : CVE-2018-15688: A buffer overflow vulnerability in the dhcp6 client of systemd allowed a malicious dhcp6 server to overwrite heap memory in systemd-networkd. bsc1113632 CVE-2018-15686: A vulnerability in unitdeserialize ...

openSUSE Security Update : systemd (openSUSE-2018-216)

This update for systemd fixes the following issues : Security issue fixed : - CVE-2017-18078: tmpfiles: refuse to chown/chmod files which are hardlinked, unless protectedhardlinks sysctl is on. This could be used by local attackers to gain privileges bsc1077925 Non Security issues fixed : - core:...

kernel: S_ISGD is not cleared when setting posix ACLs in tmpfs (CVE-2016-7097 incomplete fix)

A vulnerability was found in the Linux kernel in 'tmpfs' file system. When file permissions are modified via 'chmod' and the user is not in the owning group or capable of CAPFSETID, the setgid bit is cleared in inodechangeok. Setting a POSIX ACL via 'setxattr' sets the file permissions as well as...