CVE Vulnerabilities

CVE-2016-9774

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

Published: Mar 23, 2017 | Modified: Nov 21, 2024
CVSS 3.x
7.8
HIGH
Source:
NVD
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 2.x
7.2 HIGH
AV:L/AC:L/Au:N/C:C/I:C/A:C
RedHat/V2
RedHat/V3
Ubuntu
MEDIUM

The postinst script in the tomcat6 package before 6.0.45+dfsg-1~deb7u4 on Debian wheezy, before 6.0.35-1ubuntu3.9 on Ubuntu 12.04 LTS and on Ubuntu 14.04 LTS; the tomcat7 package before 7.0.28-4+deb7u8 on Debian wheezy, before 7.0.56-3+deb8u6 on Debian jessie, before 7.0.52-1ubuntu0.8 on Ubuntu 14.04 LTS, and on Ubuntu 12.04 LTS, 16.04 LTS, and 16.10; and the tomcat8 package before 8.0.14-1+deb8u5 on Debian jessie, before 8.0.32-1ubuntu1.3 on Ubuntu 16.04 LTS, before 8.0.37-1ubuntu0.1 on Ubuntu 16.10, and before 8.0.38-2ubuntu1 on Ubuntu 17.04 might allow local users with access to the tomcat account to obtain sensitive information or gain root privileges via a symlink attack on the Catalina localhost directory.

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
Debian_linux Debian 7.0 (including) 7.0 (including)
Debian_linux Debian 8.0 (including) 8.0 (including)
Tomcat6 Ubuntu esm-infra-legacy/trusty *
Tomcat6 Ubuntu precise *
Tomcat6 Ubuntu trusty *
Tomcat6 Ubuntu trusty/esm *
Tomcat6 Ubuntu upstream *
Tomcat7 Ubuntu precise *
Tomcat7 Ubuntu trusty *
Tomcat7 Ubuntu upstream *
Tomcat7 Ubuntu xenial *
Tomcat7 Ubuntu yakkety *
Tomcat8 Ubuntu artful *
Tomcat8 Ubuntu bionic *
Tomcat8 Ubuntu cosmic *
Tomcat8 Ubuntu upstream *
Tomcat8 Ubuntu xenial *
Tomcat8 Ubuntu yakkety *
Tomcat8 Ubuntu zesty *

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