Microsoft leaks their golden key, allowing attackers to unlock secure boot systems, a security breach at Oracle exposes hundreds of companies & Linux has an embarrassing networking stack bug.

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Security Breach at Oracle’s MICROS point of sales division

A Russian organized cybercrime group known for hacking into banks and retailers appears to have breached hundreds of computer systems at software giant Oracle Corp.
More alarmingly, the attackers have compromised a customer support portal for companies using Oracle’s MICROS point-of-sale credit card payment systems.
Asked this weekend for comment on rumors of a large data breach potentially affecting customers of its retail division, Oracle acknowledged that it had “detected and addressed malicious code in certain legacy MICROS systems.” It also said that it is asking all MICROS customers to reset their passwords for the MICROS online support portal.
Oracle’s MICROS division sells point-of-sale systems used at more than 330,000 cash registers worldwide. When Oracle bought MICROS in 2014, the company said MICROS’s systems were deployed at some 200,000+ food and beverage outlets, 100,000+ retail sites, and more than 30,000 hotels.
A source briefed on the investigation says the breach likely started with a single infected system inside of Oracle’s network that was then used to compromise additional systems. Among those was a customer “ticketing portal” that Oracle uses to help MICROS customers remotely troubleshoot problems with their point-of-sale systems.
Those sources further stated that the intruders placed malicious code on the MICROS support portal, and that the malware allowed the attackers to steal MICROS customer usernames and passwords when customers logged in the support Web site.
This breach could be little more than a nasty malware outbreak at Oracle. However, the Carbanak Gang’s apparent involvement makes it unlikely the attackers somehow failed to grasp the enormity of access and power that control over the MICROS support portal would grant them.
This [incident] could explain a lot about the source of some of these retail and merchant point-of-sale hacks that nobody has been able to definitively tie to any one point-of-sale services provider, I’d say there’s a big chance that the hackers in this case found a way to get remote access” to MICROS customers’ on-premises point-of-sale devices.

  • It is not clear if the breach at Oracle may have resulted in the attackers being able to remotely control MICROS payment terminals.
  • According to comments on the Krebs articles, the actual credit card processing is usually done on the pinpad unit, and just the results are processed by the cash register running MICROS

After investigative reporter Brian Krebs reported a compromise of Oracle’s MICROS unit earlier this week, it now appears the same allegedly Russian cybercrime gang has hit five others in the last month: Cin7, ECRS, Navy Zebra, PAR Technology and Uniwell. Together, they supply as many as, if not more than, 1 million point-of-sale systems globally.

TCP stack bug in Linux 3.6+ means many systems vulnerable

At the 25th Usenix Security Symposium on Wednesday, researchers with the University of California at Riverside and the US Army Research Laboratory will demonstrate a proof-of-concept exploit that allows them to inject content into an otherwise legitimate USA Today page that asks viewers to enter their e-mail and passwords.
Computer scientists have discovered a serious Internet vulnerability that allows attackers to terminate connections between virtually any two parties and, if the connections aren’t encrypted, inject malicious code or content into the parties’ communications.
The vulnerability resides in the design and implementation of RFC 5961, a relatively new Internet standard that’s intended to prevent certain classes of hacking attacks.

  • However, in order to prevent a denial of service attack, there is a global rate limit to the number of responses this new code will send. The issue is, an attacker can now exploit this, by eliciting enough responses to research that limit, it means that the server will not send legitimate responses to the user. This then allows the attacker to send a response pretending to be the server, and shutdown the connection between the user and the server.

Attackers can go on to exploit the flaw to shut down the connection, inject malicious code or content into unencrypted data streams, and possibly degrade privacy guarantees provided by the Tor anonymity network.
The flawed code was introduced into the Linux operating system kernel starting with version 3.6 in 2012, has added a largely complete set of functions implementing the standard. Linux kernel maintainers released a fix with version 4.7 almost three weeks ago, but the patch has not yet been applied to most mainstream distributions. For the attack to work, only one of the two targeted parties has to be vulnerable, meaning many of the world’s top websites and other services running on Linux remain susceptible.

  • What makes this attack especially bad is that the attacker does not need to be Man-in-the-Middle, it works as a so called “off-path” attack. The attacker just sits on the sidelines with their regular internet connection, and sends packets to one or both parties, and by guessing the port numbers used on each side (usually by brute force), can inject content into the flow of packets between the two parties.
  • This is normally prevented by the TCP three-way handshake (which gets a positive acknowledgement from both sides, to prevent someone from being able to spoof their IP), and the sequence numbers prevent an attacker from easily injecting packets in the connection stream.

In this paper, we discover a much more powerful off-path attack that can quickly 1) test whether any two arbitrary hosts on the Internet are communicating using one or more TCP connections (and discover the port numbers associated with such connections); 2) perform TCP sequence number inference which allows the attacker to subsequently, forcibly terminate the connection or inject a malicious payload into the connection. We emphasize that the attack can be carried out by a purely off-path attacker without running malicious code on the communicating client or server. This can have serious implications on the security and privacy of the Internet at large.
The root cause of the vulnerability is the introduction of the challenge ACK responses and the global rate limit imposed on certain TCP control packets. The feature is outlined in RFC 5961, which is implemented faithfully in Linux kernel version 3.6 from late 2012. At a very high level, the vulnerability allows an attacker to create contention on a shared resource, i.e., the global rate limit counter on the target system by sending spoofed packets. The attacker can then subsequently observe the effect on the counter changes, measurable through probing packets.
Through extensive experimentation, we demonstrate that the attack is extremely effective and reliable. Given any two arbitrary hosts, it takes only 10 seconds to successfully infer whether they are communicating. If there is a connection, subsequently, it takes also only tens of seconds to infer the TCP sequence numbers used on the connection. To demonstrate the impact, we perform case studies on a wide range of applications.

  • So the features introduced by the new RFC make it possible for the attacker to figure out the sequence number of the TCP connection to inject traffic into it

Besides injecting malicious JavaScript into a USA Today page, the researchers also show how the vulnerability can be exploited to break secure shell, or SSH, connections and tamper with communications traveling over Tor. In the latter case, attackers can terminate key links in the Tor chain—for instance, those connecting an end user to an entry node, an entry node to a middle relay, or a middle relay to the exit node. The Tor attack could be particularly effective if it knocked out properly functioning exit nodes because the technique would increase the chances that connections would instead use any malicious exit nodes that may exist.

Microsoft bungles SecureBoot key handling, golden keys can unlock any system

Microsoft has accidentally leaked the keys to the kingdom, permitting attackers to unlock devices protected by Secure Boot — and it may not be possible to fully resolve the leak.
If you provision this magic policy, that is, if you install it into your firmware, the Windows boot manager will not verify that it is booting an official Microsoft-signed operating system. It will boot anything you give it provided it is cryptographically signed, even a self-signed binary – like a shim that loads a Linux kernel.

  • This signed policy was never meant to leave the lab, but it seems it did

The Register understands that this debug-mode policy was accidentally shipped on retail devices, and discovered by curious minds including Slip and MY123. The policy was effectively inert and deactivated on these products but present nonetheless.
For internal debugging purposes, Microsoft created and signed a special Secure Boot policy that disables the operating system signature checks, presumably to allow programmers to boot and test fresh OS builds without having to sign each one.
This, in turn, allows someone with admin rights or an attacker with physical access to a machine not only to bypass Secure Boot and run any operating system they wish, such as Linux or Android, but also permits the installation and execution of bootkit and rootkits at the deepest level of the device
A backdoor, which MS put into secure boot because they decided to not let the user turn it off in certain devices, allows for secure boot to be disabled everywhere!
You can see the irony. Also the irony in that MS themselves provided us several nice “golden keys” (as the FBI would say 😉 for us to use for that purpose 🙂

  • Between June and July, Microsoft awarded a bug bounty, and pushed a fix — MS16-094. However, this fix was deemed “inadequate,” although it had somewhat mitigated the problem, resulting in a second patch, MS16-100, being issued in August.
  • This update blacklists a bunch of revoked keys and signatures so they can no longer be used, but Microsoft cannot revoke all old keys, because they are used on things like read-only installation disks

If you’re using a locked-down Secure Boot PC and you have admin rights on the box, and you want to boot something else, all the above is going to be of interest to you. If you’re an IT admin who is relying on Secure Boot to prevent the loading of unsigned binaries and drivers – such as rootkits and bootkits – then all the above is going to worry you.


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