libarchive parse_file_info Out-of-Bounds Read Vulnerability [CVE-2017-14501]

• A vulnerability in the parse_file_info function of libarchive could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on a targeted system.The vulnerability is due to an out-of-bounds read condition that could occur in the parse_file_info function, as defined in the archive_read_support_format_iso9660.c source code file of the affected software, when extracting ISO 9660 files. An attacker could exploit this vulnerability by persuading a user to extract an ISO 9660 file that submits malicious input to the targeted system. A successful exploit could cause an out-of-bounds read condition, resulting in a DoS condition.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.

CVE Number – CVE-2017-14501

Analysis

• To exploit this vulnerability, the attacker must have user-level access to the targeted system or persuade a user to extract an ISO 9660 file that submits malicious input to the system.

Safeguards

• Administrators are advised to apply the appropriate updates.
  
  Administrators are advised to allow only trusted users to have network access.
  
  Users are advised not to open email messages from suspicious or unrecognized sources. If users cannot verify that links or attachments included in email messages are safe, they are advised not to open them.
  
  Users are advised not to visit websites or follow links that have suspicious characteristics or cannot be verified as safe.
  
  Administrators are advised to use an unprivileged account when browsing the Internet.
  
  Administrators are advised to monitor critical systems.

Vendor Announcements

• The vendor has released an issue report at the following link: Issue #949

Fixed Software

• The vendor has released software updates at the following links: libarchive 3.3.3 and iso9660: validate directory record length #1042