CVE-2018-1120

Published: 17 May 2018

A flaw was found affecting the Linux kernel before version 4.17. By mmap()ing a FUSE-backed file onto a process's memory containing command line arguments (or environment strings), an attacker can cause utilities from psutils or procps (such as ps, w) or any other program which makes a read() call to the /proc/<pid>/cmdline (or /proc/<pid>/environ) files to block indefinitely (denial of service) or for some controlled time (as a synchronization primitive for other attacks).

From the Ubuntu Security Team

It was discovered that the procfs filesystem did not properly handle processes mapping some memory elements onto files. A local attacker could use this to block utilities that examine the procfs filesystem to report operating system state, such as ps(1).

Notes

this needs to be fixed in the kernel, not in procps

Status

Severity score breakdown

References

• http://www.openwall.com/lists/oss-security/2018/05/17/1
• https://ubuntu.com/security/notices/USN-3752-1
• https://ubuntu.com/security/notices/USN-3752-2
• https://ubuntu.com/security/notices/USN-3752-3
• https://ubuntu.com/security/notices/USN-3910-1
• https://ubuntu.com/security/notices/USN-3910-2
• https://www.cve.org/CVERecord?id=CVE-2018-1120
• NVD
• Launchpad
• Debian