CVE-2018-15688

It was discovered that systemd-network does not correctly keep track of a buffer size when constructing DHCPv6 packets. This flaw may lead to an integer underflow that can be used to produce an heap-based buffer overflow. A malicious host on the same network segment as the victim's one may advertise itself as a DHCPv6 server and exploit this flaw to cause a Denial of Service or potentially gain code execution on the victim's machine.

This issue affects the versions of systemd-networkd as shipped with Red Hat Enterprise Linux 7, however the package is available only through the unsupported Optional repository and it cannot be exploited unless the interface is explicitly configured to use DHCP.

This issue affects the versions of NetworkManager as shipped with Red Hat Enterprise Linux 7 because the package includes some parts of the systemd-networkd code, which present the same vulnerability. NetworkManager is vulnerable to this flaw only when configured to use the internal DHCP, which is not the default. However, when it is, the flaw may be triggered by a connection where either ipv6.method is set to dhcp or it is set to auto, which is the default value.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.