Dropping privileges

If you’re writing a tool that takes untrusted input, and you should treat almost all input as untrusted, then it’s a good idea to add a layer of defense against bugs in your code.

What good is a buffer overflow, if the process is fully sandboxed?

This applies to both processes running as root, and as normal users. Though there are some differences.

Standard POSIX

In POSIX you can only sandbox if you are root. The filesystem can be hidden with chroot(), and you can then change user to be non-root using setuid() and setgid().

There have been ways to break out of a chroot() jail, but if you make sure to drop root privileges then chroot() is pretty effective at preventing opening new files and running any new programs.

But which directory? Ideally you want it to be:

• read-only by the process (after dropping root)
• empty
• not shared by any other process that might write to it

The best way no ensure this is probably to create a temporary directory yourself, owned by root.

This is pretty tricky to do, though:

// Return 0 on success.
int do_chroot()
{
  const char* tmpdir = getenv("TMPDIR");
  if (tmpdir == NULL)  Continue reading

Ethernet Switching Keeps Rising Despite Supply Chain Woes

Whenever demand exceeds supply, inflation is inevitable. And it is not at all surprising to find that in certain sectors of the networking space, the cost of bandwidth is flattening out instead of decreasing and in some cases is on the rise. …

Ethernet Switching Keeps Rising Despite Supply Chain Woes was written by Timothy Prickett Morgan at The Next Platform.

COVID, slow endpoint deployment could put the brakes on private 5G growth

The pace of private 5G/LTE growth in the enterprise is likely to drop substantially below earlier estimates, thanks to Covid's aftereffects and slack growth in the development of 5G-equipped endpoints, according to a report issued today by IDC.A December 2020 forecast predicted the size of the annual market for private LTE/5G wireless infrastructure to reach roughly $4.7 billion in 2023, but that figure has been revised downward to about $3.8 billion in the new report. That's still a sharp increase from 2021's $1.8 billion figure, but a substantial change, nonetheless.To read this article in full, please click here

DHCP defined and how it works

If Dynamic Host Configuration Protocol (DHCP) didn’t exist, network administrators would have to manually parcel out IP addresses from the available pool, which would be prohibitively time consuming, inefficient, and error prone. Fortunately, DHCP does exist.What is DHCP and how does it work? DHCP is an under-the-covers mechanism that automates the assignment of IP addresses to fixed and mobile hosts that are connected wired or wirelessly.When a device wants access to a network that’s using DHCP, it sends a request for an IP address that is picked up by a DHCP server. The server responds be delivering an IP address to the device, then monitors the use of the address and takes it back after a specified time or when the device shuts down. The IP address is then returned to the pool of addresses managed by the DHCP server to be reassigned to another device as it seeks access to the network.To read this article in full, please click here

The Case for Full-Stack Observability with Business Context

Cisco Enterprise Networks Presents at Tech Field Day Exclusive with Cisco 2022

I am honored to be welcomed back to Tech Field Day Exclusive with Cisco scheduled on 16-17 March 2022. It will be a live-streamed event that you can watch over on the Tech Field Day site during the event, or on their YouTube channel shortly after.

The schedule for the event is as follows:

See you there!

Cisco Enterprise Networks Presents at Tech Field Day Exclusive with Cisco 2022

I am honored to be welcomed back to Tech Field Day Exclusive with Cisco scheduled on 16-17 March 2022. It …

Continue reading →

Tech Bytes: Integrating Digital Experience Management And Cloud-Delivered Security (Sponsored)

Tech Bytes: Integrating Digital Experience Management And Cloud-Delivered Security (Sponsored)

Today on the Tech Bytes podcast we focus on the intersection of security and digital experience management. With more applications moving to the cloud, IT has to provide secure access while also ensuring a good user experience. Our sponsor Netskope, which provides cloud-based security services, has ideas on how to make this happen.

The post Tech Bytes: Integrating Digital Experience Management And Cloud-Delivered Security (Sponsored) appeared first on Packet Pushers.

BGP Policies (Part 2)

At the most basic level, there are only three BGP policies: pushing traffic through a specific exit point; pulling traffic through a specific entry point; preventing a remote AS (more than one AS hop away) from transiting your AS to reach a specific destination. In this series I’m going to discuss different reasons for these kinds of policies, and different ways to implement them in interdomain BGP.

There are many reasons an operator might want to select which neighboring AS through which to send traffic towards a given reachable destination (for instance, 100::/64). Each of these examples assumes the AS in question has learned multiple paths towards 100::/64, one from each peer, and must choose one of the two available paths to forward along.

In the following network—

From AS65004’s perspective…

Transit providers primarily choose the most optimal exit from their AS to reduce the amount of peering settlement they are paying by using and maintaining settlement-free peering where possible and reducing the amount of time and distance traffic is carried through their network (through hot potato routing, discussed in more detail below).
If, for instance, AS65004 has a paid peering relationship with AS65002, and a contract with AS65003 which Continue reading

#VMwareNSXChat Recap: NSX-T 3.2

In our most recent Twitter chat, we were joined by Vivek Bhandari, Varun Santosh, and Srini Nimmagadda to answer common questions about NSX-T 3.2, its benefits, how it works, and more. Dive in below for the full recap of our NSX-T 3.2 #VMwareNSXChat.

Question 1: If you had to describe NSX-T 3.2 to a friend using just one sentence (or using just 280 characters) what would you say? #VMwareNSXChat

Varun: Stronger security, simplified networking, easy operations – what’s not to like #VMwareNSXchat!

Vivek: It’s like going from a flip phone to a touch screen smartphone. Gamechanger! #VMwareNSXChat

Question 2: What are the key Networking and Policy enhancements? #VMwareNSXChat

Varun: NSX-T 3.2 simplifies network provisioning thru prescriptive NSX deployment from vCenter, deeper integration with Antrea, Federation support for VM tag replication, enhanced migration coordinator, and enhanced monitoring and troubleshooting. #VMwareNSXChat

Question 3: What are the key security enhancements? #VMwareNSXChat

Vivek: NSX-T 3.2 is a quantum leap forward bringing advanced security in a distributed architecture. It now includes network traffic analysis (NTA) and network detection and response (NDR), malware prevention with sandboxing, L7 gateway firewall, and more. #VMwareNSXChat

Vivek: Of Continue reading

Network Break 373: Google Buys Mandiant To Bolster Security Ops; Network OS DENT 2.0 Released

Architecting Memory Pools For HPC And AI Applications Using CXL

Over the past decade, much of the focus with machine learning has been on CPUs and accelerators, primarily GPUs but also custom ASICs, with advances in the chip architecture aimed at boosting parallel math performance. …

Architecting Memory Pools For HPC And AI Applications Using CXL was written by Jeffrey Burt at The Next Platform.

Real-time EVPN fabric visibility

docker run --rm -it --privileged --network host --pid="host" \
  -v /var/run/docker.sock:/var/run/docker.sock -v /run/netns:/run/netns \
  -v ~/clab:/home/clab -w /home/clab \
  ghcr.io/srl-labs/clab bash

curl -O https://raw.githubusercontent.com/sflow-rt/containerlab/master/evpn3.yml

containerlab deploy -t evpn3.yml

docker exec -it clab-evpn3-leaf1 vtysh -c "show running-config"

Building configuration...

Current configuration:
!
frr version 8.1_git
frr defaults datacenter
hostname leaf1
no ipv6 forwarding
log stdout
!
router bgp 65001
 bgp bestpath as-path multipath-relax
 bgp bestpath compare-routerid
 neighbor fabric peer-group
 neighbor fabric remote-as external
 neighbor fabric description Internal Fabric Network
 neighbor fabric capability extended-nexthop
 neighbor eth1 interface peer-group fabric
 neighbor eth2 interface peer-group fabric
 !
 address-family ipv4 unicast
  network 192.168.1.1/32
 exit-address-family
 !
 address-family l2vpn evpn
  neighbor fabric activate
  advertise-all-vni
 exit-address-family
exit
!
ip nht resolve-via-default
!
end

Two Simple Ways Automation Can Save You Money on Your AWS Bill

Red Hat Ansible Automation Platform is an excellent automation and orchestration tool for public clouds. For this post, I am going to walk through two common scenarios where Ansible Automation Platform can help out. I want to look outside the common public cloud use-case of provisioning and deprovisioning resources and instead look at automating common operational tasks.

What is an operational task? It is simply anything that an administrator has to do outside of creating and deleting cloud resources (e.g. instances, networks, keys, etc.) to help maintain their company's public cloud account. One of the problems I’ve encountered is instances being left on, running up our public cloud bill in the background while we were focusing our attention elsewhere. The more users you have, the more likely problems are to occur; automation can help address these issues and maintain control of your account. There are two common scenarios I want to address here:

1. Bespoke AWS instances were manually created for a one-off initiative, usually to test something, then instances were forgotten about and left running.
2. Continuous Integration (CI) instances were spun up to test changes programmatically every time a Pull Request (PR) went into our project, and would Continue reading

Democratizing email security: protecting individuals and businesses of all sizes from phishing and malware attacks

Since our founding, Cloudflare has been on a mission to take expensive, complex security solutions typically only available to the largest companies and make them easy to use and accessible to everyone. In 2011 and 2015 we did this for the web application firewall and SSL/TLS markets, simplifying the process of protecting websites from application vulnerabilities and encrypting HTTP requests down to single clicks; in 2020, during the start of the COVID-19 pandemic, we made our Zero Trust suite available to everyone; and today—in the face of heightened phishing attacks—we’re doing the same for the email security market.

Once the acquisition of Area 1 closes, as we expect early in the second quarter of 2022, we plan to give all paid self-serve plans access to their email security technology at no additional charge. Control, customization, and visibility via analytics will vary with plan level, and the highest flexibility and support levels will be available to Enterprise customers for purchase.

All self-serve users will also get access to a more feature-packed version of the Zero Trust solution we made available to everyone in 2020. Zero Trust services are incomplete without an email security solution, and CISA’s recent report makes that clearer Continue reading

Investigating threats using the Cloudflare Security Center

Cloudflare blocks a lot of diverse security threats, with some of the more interesting attacks targeting the “long tail” of the millions of Internet properties we protect. The data we glean from these attacks trains our machine learning models and improves the efficacy of our network and application security products, but historically hasn’t been available to query directly. This week, we’re changing that.

All customers will soon be granted access to our new threat investigations portal, Investigate, in the Cloudflare Security Center (first launched in December 2021). Additionally, we’ll be annotating threats across our analytics platform with this intelligence to streamline security workflows and tighten feedback loops.

What sorts of data might you want to look up here? Let’s say you’re seeing an IP address in your logs and want to learn which hostnames have pointed to it via DNS, or you’re seeing a cluster of attacks come from an autonomous system (AS) you’re not familiar with. Or maybe you want to investigate a domain name to see how it’s been categorized from a threat perspective. Simply enter any of those items into the omni search box, and we’ll tell you everything we know.

IPs and hostnames will be Continue reading

Get full observability into your Cloudflare logs with New Relic

Building a great customer experience is at the heart of any business. Building resilient products is half the battle — teams also need observability into their applications and services that are running across their stack.

Cloudflare provides analytics and logs for our products in order to give our customers visibility to extract insights. Many of our customers use Cloudflare along with other applications and network services and want to be able to correlate data through all of their systems.

Understanding normal traffic patterns, causes of latency and errors can be used to improve performance and ultimately the customer experience. For example, for websites behind Cloudflare, analyzing application logs and origin server logs along with Cloudflare’s HTTP request logs give our customers an end-to-end visibility about the journey of a request.

We’re excited to have partnered with New Relic to create a direct integration that provides this visibility. The direct integration with our logging product, Logpush, means customers no longer need to pay for middleware to get their Cloudflare data into New Relic. The result is a faster log delivery and fewer costs for our mutual customers!

We’ve invited the New Relic team to dig into how New Relic One can Continue reading

Leverage IBM QRadar SIEM to get insights from Cloudflare logs

It’s just gone midnight, and you’ve just been notified that there is a malicious IP hitting your servers. You need to triage the situation; find the who, what, where, when, why as fast and in as much detail as possible.

Based on what you find out, your next steps could fall anywhere between classifying the alert as a false positive, to escalating the situation and alerting on-call staff from around your organization with a middle of the night wake up.

For anyone that’s gone through a similar situation, you’re aware that the security tools you have on hand can make the situation infinitely easier. It’s invaluable to have one platform that provides complete visibility of all the endpoints, systems and operations that are running at your company.

Cloudflare protects customers’ applications through application services: DNS, CDN and WAF to name a few. We also have products that protect corporate applications, like our Zero Trust offerings Access and Gateway. Each of these products generates logs that provide customers visibility into what’s happening in their environments. Many of our customers use Cloudflare’s services along with other network or application services, such as endpoint management, containerized systems and their own servers.

We’re excited Continue reading

Introducing: Backup Certificates

At Cloudflare, we pride ourselves in giving every customer the ability to provision a TLS certificate for their Internet application — for free. Today, we are responsible for managing the certificate lifecycle for almost 45 million certificates from issuance to deployment to renewal. As we build out the most resilient, robust platform, we want it to be “future-proof” and resilient against events we can’t predict.

Events that cause us to re-issue certificates for our customers, like key compromises, vulnerabilities, and mass revocations require immediate action. Otherwise, customers can be left insecure or offline. When one of these events happens, we want to be ready to mitigate impact immediately. But how?

By having a backup certificate ready to deploy — wrapped with a different private key and issued from a different Certificate Authority than the primary certificate that we serve.

Events that lead to certificate re-issuance

Cloudflare re-issues certificates every day — we call this a certificate renewal. Because certificates come with an expiration date, when Cloudflare sees that a certificate is expiring soon, we initiate a new certificate renewal order. This way, by the time the certificate expires, we already have an updated certificate deployed and ready to use for Continue reading