The denial-of-service flaw in BIND can be triggered by specially crafted DNS packages and is capable of knocking critical servers offline.

The latest BIND update, versions 9.9.9-P3, 9.10.4-P3, and 9.11.0rc3, patched a denial-of-service flaw (CVE-2016-2776) that could be exploited using specially crafted DNS request packets. The issue was uncovered internally by ISC and affects all servers that can receive request packets from any source, ISC said in its advisory. Affected versions include 9.0.x to 9.8.x, 9.9.0 to 9.9.9-P2, 9.9.3-S1 to 9.9.9-S3, 9.10.0 to 9.10.4-P2, and 9.11.0a1 to 9.11.0rc1. ¬†Users are advised to update their BIND installations to the “patched release most closely related to your current version of BIND,” or versions 9.9.9-P3, 9.10.4-P3, and 9.11.0rc3. The fix is also in the BIND 9 Supported Preview edition as version 9.9.9-S5.

The Internet Systems Consortium (ISC) patched two vulnerabilities in domain name system software BIND, one of which was referred to as a “critical error condition” in the software. BIND is the most commonly deployed DNS server on the internet, translating domain names into IP addresses so that users can access applications and remote servers without having to track IP addresses. BIND is the de facto standard on Linux and other Unix-based machines; a vulnerability in the software affects a large number of servers and applications.

The latest BIND update, versions 9.9.9-P3, 9.10.4-P3, and 9.11.0rc3, patched a denial-of-service flaw (CVE-2016-2776) that could be exploited using specially crafted DNS request packets. The issue was uncovered internally by ISC and affects all servers that can receive request packets from any source, ISC said in its advisory.

“Testing by ISC has uncovered a critical error condition which can occur when a nameserver is constructing a response,” said the ISC, which has been maintaining BIND since 2000.

The issue is tied to a defect in the rendering of messages into packets when the nameserver is constructing a response. If the vulnerability is exploited via specially crafted requests, it could trigger an assertion failure in buffer.c while constructing a response to a specific type of a query. The exploit would succeed “even if the apparent source address isn’t allowed to make queries (i.e. doesn’t match ‘allow-query’.”)

The issue was marked high-severity with a 7.8 score on the Common Vulnerability Scoring System because it can be exploited remotely. Red Hat’s advisory says the attack doesn’t require any authentication, additional privileges, or user interaction to successfully exploit the flaw, so the issue is particularly dangerous.

It’s easy to downplay the severity of a denial-of-service flaw in a security advisory, especially when compared against privilege escalation or remote code execution. However, because BIND is central to implementing the DNS protocol on the internet, a vulnerability that could be exploited to knock systems offline would have a wide-reaching impact. A specially crafted query that could crash the name server daemon isn’t simply an inconvenience or a minor setback. It could bring portions of the internet to its knees.

ISC has not seen any evidence indicating attackers were aware of or had already exploited the vulnerability, but cautioned that all servers that can receive request packets from any source should be updated. ISC has patched the faults in its distribution, and various Linux distributions, such as Red Hat, are already shipping fixes for their own BIND implementations.

The so-called “man-in-the-cloud” attack is said to be a common flaw in most cloud-based file synchronization services.

dropbox

Hackers don’t even need your password anymore to get access to your cloud data.

Newly published research, released at the Black Hat conference in Las Vegas on Wednesday by security firm Imperva, shows how a “man-in-the-cloud” attack can grab cloud-based files — as well as infecting users with malware — without users even noticing.

The attack differs from traditional man-in-the-middle attacks, which rely on tapping data in transit between two servers or users, because it exploits a vulnerability in the design of many file synchronization offerings, including Google, Box, Microsoft, and Dropbox services.

This is not just an issue for consumers, but also businesses, which increasingly use cloud-based services to share sensitive customer and corporate data.

The report by Imperva, which has a research unit as well as having a commercial stake in the security space, said in some cases “recovery of the account from this type of compromise is not always feasible.”

The attack works by grabbing the password token, a small file that sits on a user’s devices for convenience (which saves the user from entering their password each time). When the token is obtained, either through a phishing attack or a drive-by exploit, it can be used to fool a new machine into thinking the attacker is the account’s owner. From there, the attacker can access and steal files, and even add malware or ransomware (which is on the rise) to the victim’s cloud folder, which can be used for further attacks.

Making matters worse, account owners are almost powerless. Because the tokens are tied to the user’s device, changing the account password would not lock out the attacker.