CVE Vulnerabilities

CVE-2011-2684

Improper Link Resolution Before File Access ('Link Following')

Published: Oct 23, 2017 | Modified: Nov 21, 2017
CVSS 3.x
5.5
MEDIUM
Source:
NVD
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
CVSS 2.x
2.1 LOW
AV:L/AC:L/Au:N/C:N/I:P/A:N
RedHat/V2
RedHat/V3
Ubuntu
LOW

foo2zjs before 20110722dfsg-3ubuntu1 as packaged in Ubuntu, 20110722dfsg-1 as packaged in Debian unstable, and 20090908dfsg-5.1+squeeze0 as packaged in Debian squeeze create temporary files insecurely, which allows local users to write over arbitrary files via a symlink attack on /tmp/foo2zjs.

Weakness

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

Affected Software

Name Vendor Start Version End Version
Foo2zjs Rkkda 20090908dfsg-5.1+squeeze0 (including) 20090908dfsg-5.1+squeeze0 (including)
Foo2zjs Rkkda 20110722dfsg-1 (including) 20110722dfsg-1 (including)
Foo2zjs Rkkda 20110722dfsg-3ubuntu1 (including) 20110722dfsg-3ubuntu1 (including)
Foo2zjs Ubuntu hardy *
Foo2zjs Ubuntu lucid *
Foo2zjs Ubuntu maverick *
Foo2zjs Ubuntu natty *
Foo2zjs Ubuntu upstream *

Potential Mitigations

  • Follow the principle of least privilege when assigning access rights to entities in a software system.
  • Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.

References