Rowhammer | Breaking Cybersecurity News | The Hacker News

Cybersecurity researchers from ETH Zurich have developed a new variant of the RowHammer DRAM (dynamic random-access memory) attack that, for the first time, successfully works against AMD Zen 2 and Zen 3 systems despite mitigations such as Target Row Refresh (TRR). "This result proves that AMD systems are equally vulnerable to Rowhammer as Intel systems, which greatly increases the attack surface, considering today's AMD market share of around 36% on x86 desktop CPUs," the researchers  said . The technique has been codenamed  ZenHammer , which can also trigger RowHammer bit flips on DDR5 devices for the first time. RowHammer , first publicly disclosed in 2014, is a  well-known attack  that exploits DRAM's memory cell architecture to alter data by repeatedly accessing a specific row (aka hammering) to cause the electrical charge of a cell to leak to adjacent cells. This can induce random bit flips in neighboring memory rows (from 0 to 1, or vice versa), which can

A team of security researchers from Google has demonstrated yet another variant of the Rowhammer vulnerability that targets increasingly smaller DRAM chips to bypass all current mitigations, making it a persistent threat to chip security. Dubbed "Half-Double," the new hammering technique hinges on the weak coupling between two memory rows that are not immediately adjacent to each other but one row removed in an attempt to tamper with data stored in memory and attack a system . "Unlike  TRRespass , which exploits the blind spots of manufacturer-dependent defenses, Half-Double is an intrinsic property of the underlying silicon substrate," the researchers  noted . "This is likely an indication that the electrical coupling responsible for Rowhammer is a property of distance, effectively becoming stronger and longer-ranged as cell geometries shrink down. Distances greater than two are conceivable." Rowhammer attacks are similar to  speculative execution  

Shadow apps, a segment of Shadow IT, are SaaS applications purchased without the knowledge of the security team. While these applications may be legitimate, they operate within the blind spots of the corporate security team and expose the company to attackers.  Shadow apps may include instances of software that the company is already using. For example, a dev team may onboard their own instance of GitHub to keep their work separate from other developers. They might justify the purchase by noting that GitHub is an approved application, as it is already in use by other teams. However, since the new instance is used outside of the security team's view, it lacks governance. It may store sensitive corporate data and not have essential protections like MFA enabled, SSO enforced, or it could suffer from weak access controls. These misconfigurations can easily lead to risks like stolen source code and other issues. Types of Shadow Apps  Shadow apps can be categorized based on their interac

Academics from Vrije University in Amsterdam and ETH Zurich have published a new research paper describing yet another variation of the Rowhammer attack. Dubbed  SMASH  (Synchronized MAny-Sided Hammering), the technique can be used to successfully trigger the attack from JavaScript on modern DDR4 RAM cards, notwithstanding extensive mitigations that have been put in place by manufacturers over the last seven years. "Despite their in-DRAM Target Row Refresh (TRR) mitigations, some of the most recent DDR4 modules are still vulnerable to many-sided Rowhammer bit flips," the researchers said.  "SMASH exploits high-level knowledge of cache replacement policies to generate optimal access patterns for eviction-based many-sided Rowhammer. To bypass the in-DRAM TRR mitigations, SMASH carefully schedules cache hits and misses to successfully trigger synchronized many-sided Rowhammer bit flips." By synchronizing memory requests with DRAM refresh commands, the researchers