Re: CVE-2018-17977: CentOS ipsec remote denial of service vulnerability

[Solar Designer <solar () openwall com>]

On Fri, Oct 05, 2018 at 11:46:07PM +0800, luo wrote:
> I don't know if it is correct to publish the complete information.

It is.  Linking to temporary resources like Google Drive isn't great,
but luckily your message itself includes some detail.

> > The Linux kernel 4.14.67 mishandles certain interaction among XFRM
> > Netlink messages, IPPROTO_AH packets, and IPPROTO_IP packets, which
> > allows local users to cause a denial of service (memory consumption
> > and system hang) by leveraging root access to execute crafted
> > applications, as demonstrated on CentOS 7.

Since you say that "leveraging root access to execute crafted
applications" is required, how is this a security issue?  Also, since
this setup has to be prepared locally, how is the attack "remote"?

In other words, would a sysadmin plausibly make this kind of custom
local setup, and why?  If the answer is no, then I think there's no
security issue here.

Alexander