AccountsService Insufficient Path Check Directory Traversal Vulnerability [CVE-2018-14036]

• CVE Number – CVE-2018-14036
• A vulnerability in AccountsService could allow a local attacker to conduct a directory traversal attack on a targeted system.
  
  The vulnerability is due to insufficient path checking in the user_change_icon_file_authorized_cb() function, as defined in the user.c source code file of the affected software. An attacker could exploit this vulnerability by executing an icon file that submits malicious directory traversal characters to the targeted system. An exploit could allow the attacker to conduct a directory traversal attack, which the attacker could use to access sensitive information.
  
  Proof-of-concept (PoC) code that demonstrates an exploit of this vulnerability is publicly available.
  
  The vendor has confirmed the vulnerability and released software updates.

Analysis

• To exploit this vulnerability, the attacker must have user-level access to the targeted system. This access requirement may reduce the likelihood of a successful exploit.

Safeguards

• Administrators are advised to apply the appropriate updates. Administrators are advised to allow only trusted users to access local systems. Administrators are advised to allow only privileged users to access administration or management systems. Administrators are advised to monitor critical systems.

Vendor Announcements

• The vendor has released a bug report at the following link: Bug 107085

Fixed Software

• The vendor has released software updates at the following link: user: fix insufficient path prefix check