An Encryptioner’s Conscience | TechSNAP 217

chris

7 years ago

The sad state of SMTP encryption, a new huge round of flaws has been found in consumer routers & the reviews of Intel’s new Broadwell desktop processors are in!

Plus some great questions, a huge round-up & much, much more!

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— Show Notes: —

The sad state of SMTP (email) encryption

This article talks about the problems with the way email transport encryption is done
When clients submit mail to a mail server, and when mail servers talk to each other to exchange those emails, they have the option of encrypting that communication to prevent snooping
This “opportunistic” encryption happens if the server you are connecting to (as a client, or as another server), advertises the STARTTLS option during the opening exchange
If that keyword is there, then your client can optionally send the STARTTLS command, and switch further communications to be encrypted
The first problem with this is that it happens over plain text, which has no protection against modification
Some cisco firewalls, and most bad guys, will simply modify the message from the server before it gets to you, to remove the STARTTLS keyword, so you client will assume the server just doesn’t speak TLS.
Do we maybe need something like HSTS for SMTP?
When submitting email from my client machine, I always use a special port that is ALWAYS SSL.
But this is only the beginning of the problem
SSL/TLS are designed to provide 3 guarantees:
- Authenticity: You are talking to who you think you are talking to (not someone pretending to be them). This is provided by verifying that the presented SSL Certificate is issued by a trusted CA
- Integrity: The message was not modified or tampered with by someone during transit. This is provided by the MAC (Message Authentication Code), a hash that is used to ensure the message has not been modified
- Privacy: The contents of the message are encrypted so no one else can read them. This is provided by symmetric encryption using a session key negotiated with the other side using asymmetric cryptography based on the SSL Certificate.
Mail servers rarely actually check authenticity, because many mail servers use self-signed certificates.
Many domains are hosted on one server, so the certificate is not likely to match the name of the email domain
The certificate check is done against the hostname in the MX record, but most people prefer to use a ‘vanity’ name here, mail.mydomain.com, which won’t match in2-smtp.messagingengine.com or whatever the mail server ends up being called
But, even if we did enforce this, and reject mail sent by servers with self-signed certificates, without DNSSEC, someone could just spoof the MX records, and instead of my email being sent over an encrypted channel to your server, which I have verified, I would be given an incorrect MX record, telling me to deliver mail to mx1.evilguy.com, which has a perfectly vaild SSL certificate for that domain
In the end, the better solution looks like it will be DNSSEC + DANE (publish the fingerprint of the correct SSL certificate as a DNS entry, alongside your MX record)
With this setup, you still get all 3 protections of SSL, without needing to trust the Certificate Authorities, who do not have the best record at this point
Don’t think MitM is a big deal? The ongoing problem of BGP hijacking suggests otherwise. A lot of internet traffic is getting misdirected. If it eventually makes it to its destination, people are much less likely to notice.

Researchers find 60 flaws in 22 common consumer network devices

A group of security researchers doing their IT Security Master’s Thesis at Universidad Europea de Madrid in Spain have published their research
They found serious flaws in 22 different SOHO network devices, including those from D-Link, Belkin, Linksys, Huawei, Netgear, and Zyxel
Most of the devices they surveyed were ones distributed by ISPs in Spain, so these vulnerabilities have a very large impact, since almost every Internet user in Spain has one of these 22 devices
They found 11 unique types of vulnerability, for a total of 60 flaws across the 22 devices
Persistent Cross Site Scripting (XSS)
- Unauthenticated Cross Site Scripting
- Cross Site Request Forgery (CSRF)
- Denial of Service (DoS)
- Privilege Escalation
- Information Disclosure
- Backdoor
- Bypass Authentication using SMB Symlinks
- USB Device Bypass Authentication
- Bypass Authentication
- Universal Plug and Play related vulnerabilities
All of this makes me glad my router runs FreeBSD.
Luckily, there are finally some consumer network devices like these that can run a real OS, like the TP-LINK WDR3600, which has a 560mhz MIPS CPU and can run FreeBSD 11 or Linux distros such as DD-WRT
Additional Coverage – ITWorld

CareFirst Blue Cross hit by security breach affecting 1.1 million customers

“CareFirst BlueCross BlueShield last week said it had been hit with a data breach that compromised the personal information on approximately 1.1 million customers. There are indications that the same attack methods may have been used in this intrusion as with breaches at Anthem and Premera, incidents that collectively involved data on more than 90 million Americans.”
It would be interesting to know if there are common bits of infrastructure or software in use at these providers that made these compromises possible, or if security was just generally lax enough that the attackers were able to compromise the three insurance providers separately
“According to a statement CareFirst issued Wednesday, attackers gained access to names, birth dates, email addresses and insurance identification numbers. The company said the database did not include Social Security or credit card numbers, passwords or medical information. Nevertheless, CareFirst is offering credit monitoring and identity theft protection for two years.”
“There are clues implicating the same state-sponsored actors from China thought to be involved in the Anthem and Premera attacks.”
“As Krebs noted in this Feb. 9, 2015 story, Anthem was breached not long after a malware campaign was erected that mimicked Anthem’s domain names at the time of the breach. Prior to its official name change at the end of 2014, Anthem was known as Wellpoint. Security researchers at cybersecurity firm ThreatConnect Inc. had uncovered a series of subdomains for we11point[dot]com (note the “L’s” in the domain were replaced by the numeral “1”) — including myhr.we11point[dot]com and hrsolutions.we11point[dot]com. ThreatConnect also found that the domains were registered in April 2014 (approximately the time that the Anthem breach began), and that the domains were used in conjunction with malware designed to mimic a software tool that many organizations commonly use to allow employees remote access to internal networks.”
“On Feb. 27, 2015, ThreatConnect published more information tying the same threat actors and modus operandi to a domain called “prennera[dot]com” (notice the use of the double “n” there to mimic the letter “m”)
So it seems that the compromises may have just been a combination of spear phishing and malware, to trick employees into divulging their credentials to sites they thought were legitimate
Such targeted attacks on teleworkers are a disturbing new trend
The same Chinese bulk registrant also bought careflrst[dot]com (the “i” replaced with an “L”) and caref1rst[dot]com (the “i” replaced with the number “1”).
“Additionally, ThreatConnect has unearthed evidence showing the same tactics were used on EmpireB1ue.com (note the “L” replaced with a number “1”), a domain registered April 11, 2014 (the same day as the phony Carefirst domains). EmpireBlue BlueCross BlueShield was one of the organizations impacted by the Anthem breach.”
Anthem has broken the trend, and is offering “AllClear ID” credit and identity theft monitoring, rather than Experian

First review of Intel’s new Broadwell desktop processors

The long awaited new line of desktop processors has landed
Problems with the new 14nm fabrication process resulted in the entire broadwell line being delayed, significantly in the case of the desktop chip
The two new models are the Core i7 5775c, and Core i5 5765c with a 65W TDP
These Broadwell chips are a lower TDP than the top-end Haswell cousins, actually being closer to the lower clocked i7-4790S than the top end i7-4770K
Overall, speeds are not quite as fast as the current generation Haswell flagship processors
These new processors use Intel’s Iris Pro 6200 Integrated GPU, with performance numbers that now outpace rival AMD’s offerings, although at a higher price point
Broadwell will soon be replaced by Skylake, later this year, so you might want to wait to make your next big purchase
Broadwell also features: “128MB of eDRAM that acts almost like an L4 cache. This helps alleviate memory bandwidth pressure by providing a large(ish) pool near the CPU but with lower latency and much greater bandwidth than main memory. The eDRAM has the greatest effect in graphics, but we also saw some moderate increases in our non-3D regular benchmark suite”
In the end, it is a bit unexpected for the desktop range to include only 2 processors, and in the middle TDP, with no offerings at the lower end (35W) or higher end (88W)
Some of the benchmarks suggest the eDRAM may help with video encoding