This is the story of how I found one of my favorite iOS vulnerabilities so far. It’s one of my favorites because of how simple it was to implement an exploit for it. There’s also the fact that it uses a legacy public API that’s still relied upon by many components of Apple’s operating systems, and that many developers have never heard of.

However, just as any process on the system can register to receive Darwin notifications, the same is true for sending them. Considering these properties, I began to wonder if there were places on iOS using Darwin notifications for powerful operations that could potentially be exploited as a denial-of-service attack from within a sandboxed app.

source: HN

Whilst the Isosceles and Dark Navy posts explained the underlying memory corruption vulnerability in great detail, they were unable to solve another fascinating part of the puzzle: just how exactly do you land an exploit for this vulnerability in a one-shot, zero-click setup? As we’ll soon see, the corruption primitive is very limited. Without access to the samples it was almost impossible to know.

source: HN

An attacker within bluetooth range is able to trigger navigation to a FIDO:/ URI from an attacker controlled page on a mobile browser, allowing them to initiate a legitimate PassKeys authentication intent which will be received on the attacker’s device. This results in the attacker being able to “phish” PassKeys credentials, completely breaking this assumption that PassKeys are impossible to phish.

source: HN

Critical authentication bypass vulnerabilities (CVE-2025-25291 + CVE-2025-25292) were discovered in ruby-saml up to version 1.17.0. In this blog post, we’ll shed light on how these vulnerabilities that rely on a parser differential were uncovered.

As shown once again: relying on two different parsers in a security context can be tricky and error-prone.

source: HN

It involves a combination of several cutting-edge features in the macOS kernel (XNU)- Safe Memory Reclamation (SMR), read-only page mappings, per-thread credentials, memcpy implementation details, and of course, a race condition tying everything all together. This bug allows for corruption of thread’s kauth_cred_t credential pointer. Specifically, the SMR-protected p_ucred field of a process’s read-only struct can be corrupted to point to invalid memory, or potentially to a different (maybe even more privileged) credential.

https://github.com/jprx/CVE-2025-24118

source: trivium

In this post, we first discuss the background of what microcode is, why microcode patches exist, why the integrity of microcode is important for security, and how AMD attempts to prevent tampering with microcode. Next, we focus on the microcode patch signature validation process and explain in detail the vulnerability present (using CMAC as a hash function). Finally, we discuss how to use some of the tools we’ve released today which can help researchers reproduce and expand on our work (skip to the Zentool section of this blogpost for a “how to” on writing your own microcode).

source: HN

This vulnerability allows an adversary with local administrator privileges (ring 0 from outside a VM) to load malicious microcode patches. We have demonstrated the ability to craft arbitrary malicious microcode patches on Zen 1 through Zen 4 CPUs. The vulnerability is that the CPU uses an insecure hash function in the signature validation for microcode updates. This vulnerability could be used by an adversary to compromise confidential computing workloads protected by the newest version of AMD Secure Encrypted Virtualization, SEV-SNP or to compromise Dynamic Root of Trust Measurement.

https://www.amd.com/en/resources/product-security/bulletin/amd-sb-3019.html

source: HN

Have you setup automatic disk unlocking with TPM2 and systemd-cryptenroll or clevis? Then chances are high that your disk can be decrypted by an attacker who just has brief physical access to your machine - with some preparation, 10 minutes will suffice. In this article we will explore how TPM2 based disk decryption works, and understand why many setups are vulnerable to a kind of filesystem confusion attack. We will follow along by exploiting two different real systems (Fedora + clevis, NixOS + systemd-cryptenroll).

source: HN

The research unveils a new attack surface in Windows by exploiting Best-Fit, an internal charset conversion feature. Through our work, we successfully transformed this feature into several practical attacks, including Path Traversal, Argument Injection, and even RCE, affecting numerous well-known applications!

source: HN

This book was distributed at the FIDO Authenticate conference in 2024. Its intended format was as a PDF, which you can find here.

https://www.imperialviolet.org/tourofwebauthn/tourofwebauthn.pdf

Another year, another CCC. It’s been a long road from Berlin to Leipzig and Hamburg. Each year, I repeat the ritual of going to the “Kongress”, the most amazing hacker get together in the world. The Kongress is special, hackers of all denominations meet, engage, hack, and enjoy a few mellow days towards the end of the year.

In this post, we will look at how the security of the AES-GCM mode of operation can be completely compromised when a nonce is reused.

Computers aren’t random. On the contrary, hardware designers work very hard to make sure computers run every program the same way every time. So when a program does need random numbers, that requires extra effort. Traditionally, computer scientists and programming languages have distinguished between two different kinds of random numbers: statistical and cryptographic randomness. In Go, those are provided by math/rand and crypto/rand, respectively. This post is about how Go 1.22 brings the two closer together, by using a cryptographic random number source in math/rand (as well as math/rand/v2, as mentioned in our previous post). The result is better randomness and far less damage when developers accidentally use math/rand instead of crypto/rand.

source: HN

In all of those cases except P521, the bias introduced by reducing a 512-bit number mod q is negligible. But in the case of P521, where q has 521 bits (i.e. more than 512), reducing a 512-bit number mod q has no effect at all – you get a value of k whose top 9 bits are always zero.

CVE-2024-31497

https://marc.info/?l=oss-security&m=171321011524021&w=2

After almost three years since the initial design document and hundreds of CLs in the meantime, the V8 Sandbox — a lightweight, in-process sandbox for V8 — has now progressed to the point where it is no longer considered an experimental security feature. Starting today, the V8 Sandbox is included in Chrome’s Vulnerability Reward Program (VRP). While there are still a number of issues to resolve before it becomes a strong security boundary, the VRP inclusion is an important step in that direction. Chrome 123 could therefore be considered to be a sort of “beta” release for the sandbox. This blog post uses this opportunity to discuss the motivation behind the sandbox, show how it prevents memory corruption in V8 from spreading within the host process, and ultimately explain why it is a necessary step towards memory safety.

source: HN

Deep technical analysis of the CONTINUATION Flood: a class of vulnerabilities within numerous HTTP/2 protocol implementations. In many cases, it poses a more severe threat compared to the Rapid Reset: a single machine (and in certain instances, a mere single TCP connection or a handful of frames) has the potential to disrupt server availability, with consequences ranging from server crashes to substantial performance degradation. Remarkably, requests that constitute an attack are not visible in HTTP access logs.

source: HN

In this blogpost I present several novel techniques I used to exploit a 0-day double-free bug in hardened Linux kernels (i.e. KernelCTF mitigation instances) with 93%-99% success rate. The underlying bug is input sanitization failure of netfilter verdicts. Hence, the requirements for the exploit are that nf_tables is enabled and unprivileged user namespaces are enabled. The exploit is data-only and performs an kernel-space mirroring attack (KSMA) from userland with the novel Dirty Pagedirectory technique (pagetable confusion), where it is able to link any physical address (and its permissions) to virtual memory addresses by performing just read/writes to userland addresses.

Also: https://github.com/Notselwyn/CVE-2024-1086

source: HN

Infinite loops between servers are something that must be carefully avoided to prevent performance degradation or network overload.

In light of the heightened awareness of this attack vector, now is a good time to discuss looping behavior which impacted our implementation of QUIC and review the postmortem action items that followed each event. Our experience diagnosing and mitigating attacks, as well as deploying fixes, may assist others attempting to address similar threats.

In this post, I’ll look at CVE-2023-6241, a vulnerability in the Arm Mali GPU that I reported to Arm on November 15, 2023 and was fixed in the Arm Mali driver version r47p0, which was released publicly on December 14, 2023. It was fixed in Android in the March security update. When exploited, this vulnerability allows a malicious Android app to gain arbitrary kernel code execution and root on the device. The vulnerability affects devices with newer Arm Mali GPUs that use the Command Stream Frontend (CSF) feature, such as Google’s Pixel 7 and Pixel 8 phones. What is interesting about this vulnerability is that it is a logic bug in the memory management unit of the Arm Mali GPU and it is capable of bypassing Memory Tagging Extension (MTE), a new and powerful mitigation against memory corruption that was first supported in Pixel 8. In this post, I’ll show how to use this bug to gain arbitrary kernel code execution in the Pixel 8 from an untrusted user application. I have confirmed that the exploit works successfully even with kernel MTE enabled by following these instructions.

source: HN

Senator Ron Wyden has found that the DoD banned the use of such locks for U.S. government systems, but deliberately kept information about the backdoors from the public.