Lately I've gotten random emails from friends with Yahoo Mail (or sbcglobal.net, which uses Yahoo Mail) without a subject and some random URL that I'm not going to click on.
At first I thought that someone had gotten ahold of their password, and I recommended that they update passwords.
I just now got an email from someone who changed their password last week.
Is this some sort of cross-site scripting vulnerability? Is there any way to find out from just being the recipient of one of the messages?
Here are a few of the headers from a recent mail:
Received: from [999.999.999.999] by web83806.mail.sp1.yahoo.com via HTTP; Wed, 27 Jun 2012 09:23:30 PDT X-Mailer: YahooMailWebService/0.8.118.349524 Message-ID: <1340814210.6602.YahooMailNeo@web83806.mail.sp1.yahoo.com> Date: Wed, 27 Jun 2012 09:23:30 -0700 (PDT)
The blacklisted IP in the received header was from a dynamic IP in Norway.
So I'm assuming the machine at that IP was able to get my friend's Yahoo Mail cookie and use it to send email to people in her address book. Does that sound accurate? Even if someone was using an HTTPS connection to Yahoo Mail, a specially crafted email might be able to extract the cookie and deliver it elsewhere via an RPCXML call, right?
So how do you secure a Yahoo Mail account from an attack like this?
UPDATE: I've received emails like this from four different people now. It obviously isn't an isolated incident, and there's surely something that users of Yahoo Mail can do to protect themselves.