Resolving a Mutual TLS session resumption vulnerability

On January 23, 2025, Cloudflare was notified via its Bug Bounty Program of a vulnerability in Cloudflare’s Mutual TLS (mTLS) implementation. 

The vulnerability affected customers who were using mTLS and involved a flaw in our session resumption handling. Cloudflare’s investigation revealed no evidence that the vulnerability was being actively exploited. And tracked as CVE-2025-23419, Cloudflare mitigated the vulnerability within 32 hours after being notified. Customers who were using Cloudflare’s API shield in conjunction with WAF custom rules that validated the issuer's Subject Key Identifier (SKI) were not vulnerable. Access policies such as identity verification, IP address restrictions, and device posture assessments were also not vulnerable.

Background

The bug bounty report detailed that a client with a valid mTLS certificate for one Cloudflare zone could use the same certificate to resume a TLS session with another Cloudflare zone using mTLS, without having to authenticate the certificate with the second zone.

Cloudflare customers can implement mTLS through Cloudflare API Shield with Custom Firewall Rules and the Cloudflare Zero Trust product suite. Cloudflare establishes the TLS session with the client and forwards the client certificate to Cloudflare’s Firewall or Zero Trust products, where customer policies are enforced.

mTLS operates Continue reading

Amazon Will Spend Nearly A Year Of AWS Revenue On AI Investments

There is a bit of AI spending one-upmanship going on among the hyperscalers and cloud builders – and now the foundation model builders who are partnering with their new sugar daddies to be able to afford to build vast AI accelerator estates to push the state of the art in model capabilities and intelligence.

Amazon Will Spend Nearly A Year Of AWS Revenue On AI Investments was written by Timothy Prickett Morgan at The Next Platform.

TNO015: Revolutionizing Telecom with NetOps Automation and Collaboration

Today’s episode with guest Joan Garcia provides valuable insights into the complexities of modern network operations at a telco, the importance of collaboration across technical domains, and the strategic decisions that drive innovation in the telecom industry. Joan’s experiences and perspectives offer ideas for navigating the challenges of integrating different layers of network architecture while... Read more »

Cloudflare incident on February 6, 2025

Multiple Cloudflare services, including our R2 object storage, were unavailable for 59 minutes on Thursday, February 6, 2025. This caused all operations against R2 to fail for the duration of the incident, and caused a number of other Cloudflare services that depend on R2 — including Stream, Images, Cache Reserve, Vectorize and Log Delivery — to suffer significant failures.

The incident occurred due to human error and insufficient validation safeguards during a routine abuse remediation for a report about a phishing site hosted on R2. The action taken on the complaint resulted in an advanced product disablement action on the site that led to disabling the production R2 Gateway service responsible for the R2 API.  

Critically, this incident did not result in the loss or corruption of any data stored on R2. 

We’re deeply sorry for this incident: this was a failure of a number of controls, and we are prioritizing work to implement additional system-level controls related not only to our abuse processing systems, but so that we continue to reduce the blast radius of any system- or human- action that could result in disabling any production service at Cloudflare.

What was impacted?

Continue reading

How Much Money Does Arm Make In The Datacenter?

As we have been saying for quite some time, when it comes to datacenter CPUs, we think that homegrown Arm processors (as well as those made by independents Ampere Computing and Huawei Technologies) will eventually represent at least half of the computing capacity that the hyperscalers and major cloud builders install.

How Much Money Does Arm Make In The Datacenter? was written by Timothy Prickett Morgan at The Next Platform.

Automation Workflow with Infrahub, Nornir & Jinja2

Originally published in https://www.opsmill.com/simplifying-network-automation-workflows-with-infrahub-nornir-and-jinja2/
Automation Workflow with Infrahub, Nornir & Jinja2

In this blog post, we will explore how InfraHub integrates with Jinja2 and Nornir to simplify network automation workflows. To demonstrate, we'll add two Arista devices to InfraHub, treating them as basic access switches. We'll then input the necessary details for these devices to generate configurations. We'll focus on creating VLAN and some interface configurations to keep it simple.

For each device, we'll assign a primary IP (used for SSH), configure a few interfaces with descriptions, and specify an untagged VLAN for each interface. Additionally, we'll define these VLANs globally in InfraHub (not tied to any specific device). A Jinja2 template will then use this information to generate configurations for each device. Finally, we'll use the nornir-infrahub plugin as the inventory source and Napalm to push the generated configurations to each device.

Getting Started with Infrahub
If you’re in the network automation space or attended one of the last two Autocon events, you might have come across a new tool called ‘Infrahub’ from OpsMill
Automation Workflow with Infrahub, Nornir & Jinja2

Prerequisites

This blog post assumes you are somewhat familiar with Git and Docker. If you’re new to InfraHub, don’t worry, you should still be able to follow Continue reading

Group Similar Links in netlab Topologies

In the Concise Link Descriptions blog post, I described various data formats that you could use to concisely list nodes attached to a link. Today, we’ll focus on a mechanism that helps you spot errors in your topology: a dictionary of links.

Imagine you have a large topology with dozens of links, and you get an error saying, “there is this problem with links[17]”. It must be great fun counting the links to find which one triggered the error, right?

D2DO264: Serverless Goes Mainstream

Serverless is mature enough now to be a mainstream choice for application development. But that doesn’t mean interesting things aren’t happening. Benjamen Pyle joins Kyler and Ned on Day Two DevOps to talk about the potential for small vendors and startups to develop high-quality services purpose-built to solve specific problems. They also discuss the benefits... Read more »

Cloudflare’s commitment to advancing Public Sector security worldwide by pursuing FedRAMP High, IRAP, and ENS

Today, we announced our commitment to achieving the US Federal Risk and Authorization Management Program (FedRAMP) - High, Australian Infosec Registered Assessors Program (IRAP), and Spain’s Esquema Nacional de Seguridad (ENS) as part of Cloudflare for Government. As more and more essential services are being shifted to the Internet, ensuring that governments and regulated industries have industry standard tools is critical for ensuring their uptime, reliability and performance.

What sets Cloudflare for Government apart?

Cloudflare’s network spans more than 330 cities in over 120 countries, where we interconnect with approximately 13,000 network providers in order to provide a broad range of services to millions of customers. Our network is our greatest strength to provide resiliency, security, and performance. So instead of creating a siloed government network that has limited access to our products and services, we decided to build the unique government compliance capabilities directly into our platform from the very beginning. We accomplished this by delivering critical controls in three key areas: traffic processing, management, and metadata storage.

The benefit of running the same software across our entire network is that it enables us to leverage our global footprint, and then make smart choices about how to Continue reading

Please Wait While We’re Preparing Your Interfaces

Once a virtual machine running a network operating system boots, you’d expect its data-plane interfaces to be operational, right? Some vendors disagree. It takes over a minute for some network operating systems to figure out they have this thing called interfaces.1

I would love to figure out what takes them so long (a minute is an eternity on modern CPUs), but I guess we’ll never know.

Behind the Scenes

netlab uses two device provisioning mechanisms: it can start virtual machines with Vagrant or containers with containerlab. Some of those containers might use KVM/QEMU to run a hidden virtual machine (see also: RFC 1925 rule 6a).

PP048: News Roundup – 5G Vulnerabilities Abound, CSRB Disbanded, Magic Packets Target Juniper Routers, and More

JJ and Drew catch you up on cybersecurity news including new research that uncovers a host of 5G/LTE vulnerabilities, the chain of breaches in a BeyondTrust attack that led to infiltration of the US Treasury Dept., and a lawsuit against LinkedIn alleging that data from paying customers was used to train AI models. Researchers unpack... Read more »

No hallucinations here: track the latest AI trends with expanded insights on Cloudflare Radar

During 2024’s Birthday Week, we launched an AI bot & crawler traffic graph on Cloudflare Radar that provides visibility into which bots and crawlers are the most aggressive and have the highest volume of requests, which crawl on a regular basis, and more. Today, we are launching a new dedicated “AI Insights” page on Cloudflare Radar that incorporates this graph and builds on it with additional metrics that you can use to understand AI-related trends from multiple perspectives. In addition to the traffic trends, the new section includes a view into the relative popularity of publicly available Generative AI services based on 1.1.1.1 DNS resolver traffic, the usage of robots.txt directives to restrict AI bot access to content, and open source model usage as seen by Cloudflare Workers AI.

Below, we’ll review each section of the new AI Insights page in more detail.

AI bots and crawlers traffic trends

Tracking traffic trends for AI bots can help us better understand their activity over time. Initially launched in September 2024 on Radar’s Traffic page, the AI bot & crawler traffic graph has moved to the AI Insights page and provides visibility into traffic trends gathered globally over Continue reading