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New Rowhammer variant bypasses DDR4 protection mechanisms New Rowhammer variant bypasses DDR4 protection mechanisms

Security

New Rowhammer variant bypasses DDR4 protection mechanisms

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The Blacksmith attack demonstrates that modern DDR4 modules are still vulnerable to Rowhammer.

Specialists of the Comsec computer security group of the Swiss Higher Technical School of Zurich have developed a new fuzzing technique called Blacksmith that revives the famous Rowhammer attack on modern DRAM devices and circumvents existing defense mechanisms against it. Blacksmith demonstrates that modern DDR4 modules are vulnerable as well.

Rowhammer is an attack based on the leakage of electrical charges between adjacent memory cells and allows attackers to manipulate (flip) bits. This powerful attack can bypass all software security mechanisms and allows for privilege escalation, memory corruption, and more.

Rowhammer was first introduced in 2014 and two privilege escalation exploits were published during the year.

Security fixes designed to protect against Rowhammer began to prove untenable in March 2020 when researchers showed workarounds.

Manufacturers have implemented a Target Row Refresh (TRR) security mechanism that is mostly effective against DDR4. The TRR bypass attack is called TRRespass, and is based on fuzzing.

TRRespass was able to find effective bit patterns in 14 of 40 DIMMs tested. That is, the attack is effective in 37.5% of cases. However, Blacksmith found effective Rowhammer patterns on all 40 DIMMs tested.

In the course of the study, the specialists did not look for patterns of manipulation with bits at regular intervals, but tried to find patterns of non-uniform impact on the bits, allowing to bypass TRR.

The researchers used the order, regularity, and intensity parameters to develop Rowhammer frequency patterns and then sent them to a Blacksmith fuzzer to determine operating values. This, in fact, revealed new operational potential that previous studies had missed, as shown in the video below.

Fuzzer worked for 12 hours and gave the optimal parameters for use in the Blacksmith attack. Using these values, the researchers were able to flip bits in a contiguous 256MB region of memory. In an effort to prove that the attack could be used in real-world scenarios, the team conducted test attacks that allowed them to obtain private keys for the RSA-2048 public keys used to authenticate to the SSH host.

The team found that while the use of ECC DRAM makes the attack more difficult, there is no defense against Rowhammer that way.

Upgrading to the newer DDR5 DRAM modules already available on the market will help solve the problem. In DDR5, the TRR engine has been replaced with a new system that tracks activations in the bank and issues selective updates when a threshold is reached. This means that scalable fuzzing on a DDR5 DRAM device will be much more difficult and possibly much less efficient, but this remains to be seen.

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Vulnerability found in the Apple M1 processor that cannot be closed programmatically

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Vulnerability found in the Apple M1 processor that cannot be

Specialists from the Computer Science and Artificial Intelligence Laboratory (CSAIL) from the Massachusetts Institute of Technology said that they were able to develop a PACMAN attack technique, which is possible due to a hardware vulnerability in the Apple M1 processor. Moreover, it cannot be closed by software.

Vulnerability found in the Apple M1 processor that cannot be closed programmatically

The attack itself is carried out using software and hardware, and it can be performed remotely. The PACMAN attack makes it possible to gain access to the kernel of the operating system. At the same time, potentially the same vulnerabilities can be in Qualcomm and Samsung processors, but this has not yet been confirmed.

The technical side of the attack is based on the Pointer Authentication function. It is used to check Pointer Authentication Codes (PACs), allowing only code-signed software to run. However, the PACMAN method allows you to select the necessary PAC values. In part, this technique is similar to Specter and Meltdown in Intel processors.

At the same time, Apple spokesman Scott Radcliffe said that the vulnerability does not pose an immediate threat to users and is not sufficient in itself to bypass operating system protections.

A few years ago, a vulnerability was already found in Arm processors that allows an attacker to gain unauthorized access to data.

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Security

So much for Unisoc. Companies have discovered a vulnerability in single-chip systems

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So much for Unisoc Companies have discovered a vulnerability in

Unisoc is actively capturing the market for single-chip systems, although it does so exclusively in the budget segment itself. However, it turned out that these platforms have a critical vulnerability.

So much for Unisoc.  Companies have discovered a vulnerability in single-chip systems

According to the source, the problem is in the modem’s firmware and affects both 4G and 5G platforms. The vulnerability, numbered CVE-2022-20210, was discovered while scanning Non-Access Stratum (NAS) message handlers. This vulnerability could be used to neutralize or block the device’s cellular capabilities.

The vulnerability was first discovered in the Motorola Moto G20 smartphone based on the Unisoc T700 SoC. But in the end it turned out that the same vulnerability occurs in other platforms, however, the source did not provide a list.

The Check Point specialists who discovered the vulnerability notified Unisoc back in May, and the company has already released a fix, so smartphone owners should not worry now if they update the software of their devices.

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Security

New vulnerability in Microsoft Office is heavily exploited by hackers

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New vulnerability in Microsoft Office is heavily exploited by hackers

A serious vulnerability has been found in the Microsoft Office suite that could potentially allow attackers to execute arbitrary code.

New vulnerability in Microsoft Office is heavily exploited by hackers

She was assigned the number CVE-2022-30190, and among the researchers they gave the name Follina. As noted in Kaspersky Lab, the most unpleasant thing is that there is no fix yet, and in the meantime, the vulnerability is already being actively exploited by attackers. Vulnerability CVE-2022-30190 threatens all operating systems of the Windows family, both regular and server.

While the update is being developed, experts recommend that all Windows users and administrators take advantage of temporary workarounds. As a Microsoft workaround recommends disable the MSDT URL protocol.

The CVE-2022-30190 vulnerability itself is contained in the Microsoft Windows Support Diagnostic Tool (MSDT), but due to the implementation of this tool, a single malicious office document is enough to exploit the vulnerability.

The scheme could be like this. Attackers create a malicious office document and slip it to the victim, for example by sending an email with an attachment. The infected file contains a link to an HTML file that contains JavaScript code that executes malicious code on the command line via MSDT. As a result, attackers are able to install programs, view, modify or destroy data, as well as create new accounts – that is, do everything that the privileges of the user who opened the infected file allow.

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