Application Security

New Software Side-Channel Attack Raises Risk for Captured Crypto

The new attack hits operating systems, not chips, and may give criminals the keys to a company's cryptography.

A new side-channel attack that bypasses specific chips for a hardware-agnostic, operating system-based approach, has been published by a team of researchers. The attack — with a serious security punch but no sexy name — takes advantage of a fundamental feature of modern operating systems to gain access to data that programmers and users assume will be hidden.

The attack, published in a paper titled "Page Cache Attacks," is effective against Windows and Linux — and possibly other operating systems. Furthermore, it doesn't rely on obscure or malformed instructions to the hardware: It is based on simple system calls available to relatively low authority user accounts through the operating system.

One of the researchers who found the new vulnerability is Alex Ionescu, vice president of ADR strategy at CrowdStrike. He explains the ingredients required for a successful attack on a cache: "If you have the ability to a) force things into the cache and then, b) measure or check that they're in the cache, and then c) potentially force evict them out of the cache, then you have something interesting." The group of academic and industry researchers who found the new vulnerability realized that caches don't just live in hardware; as Ionescu says, "Caches are everywhere in life."

The power of this new vulnerability is that it can examine and then exfiltrate data across an entire page of the cache, and data that is there for a number of milliseconds. Since the attacking data-check itself takes only milliseconds, there's enough time to do things like read a number of keystrokes or the clear-text response to a query involving cryptographic keys.

After looking at the potential impact of the vulnerability, Craig Young, computer security researcher for Tripwire's VERT (Vulnerability and Exposure Research Team), wrote in an email to Dark Reading, "The team has demonstrated how a fundamental concept in modern OS architecture can be abused to create covert data channels between isolated processes, log keystroke timings, spy on random number generators, and generally leak information from other processes as an unprivileged user."

Noting that the vulnerability is based on a legitimate system call in the affected operating systems, Young wrote, "This problem stems from overly permissive operating system designs giving unprivileged processes too much access to certain cache-related system calls."

That basis in system calls means that the vulnerability could be used by a different class of criminal than those that could potentially use something like Meltdown or Spectre. "The others required a lot of sophistication and knowledge and were not for the faint of heart," Mounir Hahad, head of Juniper Threat Labs at Juniper Networks, says. "This one is simpler and not hardware dependent, so it could be used by a lot of day-to-day criminals. This one doesn't need a state actor; this one can be pulled off by regular criminals."

The ease of using the attack and the data it provides is increased by application developers who take shortcuts. The paper notes examples of PHP frameworks that use the PHP function "microtime" as the pseudo-random seed for their cryptographic operations. Since the attack can capture the microtime return and the call to the cryptographic generator, an attacker could learn the basis for the encryption, making decryption much easier.

Ionescu says that mitigation is possible, but it requires both operating system vendors and application developers to look at their code, acknowledge that a vulnerability exists, and patch for it. And Hahad notes that these patches are both good news and bad news for the enterprise.

"Given how people patch their OSes, it will be a long time before the patches are all applied," he says. "On the other hand, there's not much an administrator can do aside from the patch. It's not like there's something I can do proactively to prevent someone from exploiting it. You just have to wait for the patch to come out and apply it as quickly as possible."

Related content:

Curtis Franklin Jr. is Senior Editor at Dark Reading. In this role he focuses on product and technology coverage for the publication. In addition he works on audio and video programming for Dark Reading and contributes to activities at Interop ITX, Black Hat, INsecurity, and ... View Full Bio

Comment  | 
Print  | 
More Insights
Comments
Threaded  |  Newest First  |  Oldest First
Government Shutdown Brings Certificate Lapse Woes
Curtis Franklin Jr., Senior Editor at Dark Reading,  1/11/2019
Register for Dark Reading Newsletters
White Papers
Video
Cartoon Contest
Current Issue
The Year in Security 2018
This Dark Reading Tech Digest explores the biggest news stories of 2018 that shaped the cybersecurity landscape.
Flash Poll
How Enterprises Are Attacking the Cybersecurity Problem
How Enterprises Are Attacking the Cybersecurity Problem
Data breach fears and the need to comply with regulations such as GDPR are two major drivers increased spending on security products and technologies. But other factors are contributing to the trend as well. Find out more about how enterprises are attacking the cybersecurity problem by reading our report today.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2019-6487
PUBLISHED: 2019-01-18
TP-Link WDR Series devices through firmware v3 (such as TL-WDR5620 V3.0) are affected by command injection (after login) leading to remote code execution, because shell metacharacters can be included in the weather get_weather_observe citycode field.
CVE-2018-20735
PUBLISHED: 2019-01-17
** DISPUTED ** An issue was discovered in BMC PATROL Agent through 11.3.01. It was found that the PatrolCli application can allow for lateral movement and escalation of privilege inside a Windows Active Directory environment. It was found that by default the PatrolCli / PATROL Agent application only...
CVE-2019-0624
PUBLISHED: 2019-01-17
A spoofing vulnerability exists when a Skype for Business 2015 server does not properly sanitize a specially crafted request, aka "Skype for Business 2015 Spoofing Vulnerability." This affects Skype.
CVE-2019-0646
PUBLISHED: 2019-01-17
A Cross-site Scripting (XSS) vulnerability exists when Team Foundation Server does not properly sanitize user provided input, aka "Team Foundation Server Cross-site Scripting Vulnerability." This affects Team.
CVE-2019-0647
PUBLISHED: 2019-01-17
An information disclosure vulnerability exists when Team Foundation Server does not properly handle variables marked as secret, aka "Team Foundation Server Information Disclosure Vulnerability." This affects Team.