3.3 - USN-1077-1

Executive Summary

Summary
Title	FUSE vulnerabilities

Informations
Name	USN-1077-1	First vendor Publication	2011-02-28
Vendor	Ubuntu	Last vendor Modification	2011-02-28
Severity (Vendor)	N/A	Revision	N/A

Security-Database Scoring CVSS v3

Cvss vector : N/A
Overall CVSS Score	NA
Base Score	NA	Environmental Score	NA
impact SubScore	NA	Temporal Score	NA
Exploitabality Sub Score	NA

Calculate full CVSS 3.0 Vectors scores

Security-Database Scoring CVSS v2

Cvss vector : (AV:L/AC:M/Au:N/C:N/I:P/A:P)
Cvss Base Score	3.3	Attack Range	Local
Cvss Impact Score	4.9	Attack Complexity	Medium
Cvss Expoit Score	3.4	Authentication	None Required
Calculate full CVSS 2.0 Vectors scores

Detail

A security issue affects the following Ubuntu releases:

Ubuntu 8.04 LTS Ubuntu 9.10 Ubuntu 10.04 LTS Ubuntu 10.10

This advisory also applies to the corresponding versions of Kubuntu, Edubuntu, and Xubuntu.

The problem can be corrected by upgrading your system to the following package versions:

Ubuntu 8.04 LTS:
fuse-utils 2.7.2-1ubuntu2.3

Ubuntu 9.10:
fuse-utils 2.7.4-1.1ubuntu4.5

Ubuntu 10.04 LTS:
fuse-utils 2.8.1-1.1ubuntu3.1

Ubuntu 10.10:
fuse-utils 2.8.4-1ubuntu1.3

In general, a standard system update will make all the necessary changes.

Details follow:

It was discovered that FUSE would incorrectly follow symlinks when checking mountpoints under certain conditions. A local attacker, with access to use FUSE, could unmount arbitrary locations, leading to a denial of service.