dhcpcd dhcp6_findna() Function Buffer Overflow Arbitrary Code Vulnerablity [CVE-2019-11577]

CVE Number – CVE-2019-11577

A vulnerability in the DHCPv6 implementation in dhcpcd could allow an unauthenticated, remote attacker to execute arbitrary code on a targeted system. The vulnerability exists because the dhcp6_findna() function, as defined in the src/dhcp6.c source code file of the affected software, does not properly handle reading certain addresses.

An attacker could exploit this vulnerability by sending requests that submit malicious input to the affected system. A successful exploit could allow the attacker to execute arbitrary code on the system. The vendor has confirmed the vulnerability and released software updates.

Analysis

• To exploit this vulnerability, the attacker must send a request to the targeted system, making exploitation more difficult in environments that restrict network access from untrusted sources.

Safeguards

• Administrators are advised to apply the appropriate updates.
  
  Administrators are advised to allow only trusted users to have network access.
  
  Administrators are advised to run both firewall and antivirus applications to minimize the potential of inbound and outbound threats.
  
  Administrators may consider using IP-based access control lists (ACLs) to allow only trusted systems to access the affected systems.
  
  Administrators can help protect affected systems from external attacks by using a solid firewall strategy.
  
  Administrators are advised to monitor affected systems.

Vendor Announcements

• The vendor has published a release announcement at the following link: dhcpcd-7.2.1 has been released

Fixed Software

• The vendor has published source code and software updates at the following links: DHCPv6: Fix a potential buffer overflow reading NA/TA addresses and dhcpcd – a DHCP client