HN user
Security Engineer in NZ
What have you blocked the attacker from doing?
Not blocked necessarily, but if they want to leverage a stolen token, they’re now forced down a more difficult and highly visible pathway.
You can imagine anomaly detection along the lines if “hey your rails app just made a type of request that it has never made before”, but even just monitoring the metrics of the proxy could tip you off if something is going on.
That being said, you could probably create a pair of colliding images, give one to a news outlet or something, then later post the second (presumably banned) one. The app would on short notice need to decide between banning neither or banning both.
Yeah they did this - except the contraband was automatically recognised and both images were banned via hash.
Ignoring MD5/image format-specific collision realities, theoretically an attacker could submit a contraband image that collides with a valid, allowed image they may want to remove.
When action is taken on the first image, the collided image could also be censored.
Not for me - seems it depends on libssl1.0 and buster ships 1.1
Clips were autoplaying in the live updates tab of twitter.
It has good in-kernel support for virtio drivers (e.g. kvm, bhyve, vmware) and can also run domU in the latest release.
It doesn't support "vmware tools" as such, but does support the virtual interfaces for network, disk, ballooning etc...
Well, it's not obsolete - more incomplete. OpenBSD has supported ipv6 natively for a long, long time.
Additionally, with a "home/office" router, there's many ways that IPv6 may be implemented by their ISP (e.g. static configured prefix, DHCPv6, prefix delegation etc...) all which require specific configuration on the WAN and LAN side to make it work.
So, I agree, but splitting that particular part into a different FAQ/walkthrough is going to be a better approach.
Not 100% sure, but I think this is to mitigate exploitation of UAF (Use After Free) flaws.
Adding an unpredictable delay in between when an application frees some memory, and it becomes available for reuse elsewhere will likely reduce the window of vulnerability where an exploit may be able to leverage the issue.
anyone wanting to know OpenBSD's position on virtualization should spend 20m-1hr digging through threads like that
Okay, okay. Personally, I think the fact that OpenBSD did not support any of the current virtualisation solutions, and now have an appropriate one in the works says a lot about their position.
And, frankly, what use is an organisations "position" on VM hosting to a user? It either supports it or it doesn't, and if you don't plan on developing it the reasons don't really matter.
EDIT: I'm also going to point out that mailing list posts in general rarely stand on their own, and exist within a context.
If you actually read the thread he was reacting to the premise that: as a secure operating system, OpenBSD should implement virtualisation (in this case, Xen) due to its security benefits.
A premise which he rightly shat directly on, and is his statement is completely congruent with the presence of a VM hypervisor in OpenBSD.
Is this really a compromise?
OpenBSD has happily run as a guest for a long time now, with various virtio drivers being added some time ago. Solutions like virtualbox and xen reach far into the system and are still a no-go on OpenBSD.
vmm on the other hand is a very literal OpenBSD implementation of a hypervisor. Minimal cruft means very little device emulation, virtio support only etc... The code is simple and readable[1], as opposed to other monstrosities.
I would take a punt and guess that the reason OpenBSD hasn't had a hypervisor is that a) all of the current solutions were inappropriate, and b) nobody had the time/effort to implement an appropriate one.
[1] http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/sys/arch/amd64/...
On the flip side, if they were offering TLS services to these sites, they're literally man-in-the-middling encrypted comms to those sites. And in scope of US law-enforcement/intel collection.
Might be that they were asked to continue to provide services.
OpenBSD has had VirtIO (supported by KVM, VMWare and now virtualbox too) guest support for a while now.
AWS uses Xen and domU support is a lot more invasive - OpenBSD had supported it in the past but I believe it was dropped?
How do you justify the 1.3% share on servers[1]?
OpenBSD is a research operating system.
A lot of their development and deployment methods do not align with the needs/wants of large infrastructure deployments (e.g. biannual releases, supported for 1 year).
Happy to cull/reinvent legacy to suit modern systems and practices (e.g. utf8, doas, opensmtpd/ntpd/bgpd/sshd etc...)
Refusal to support hardware without documentation or binary kernel blobs.
Focus on simplicity and correctness, rather than legacy and kludges, which often gets in the way of sysadmins wanting to Get Stuff Working.
Take your pick?
Theo has been softening on x86 virt for a long time.
Additionally, he's still right. Don't rely on it to enforce security boundries (e.g. host untrusted systems and trusted systems on different tin) and his rant is totally congruent with virtualisation having a place in OpenBSD
I guess the goal of Security is to not become the next OPM or Hacking Team.
I agree with what you say regarding perimeter security, a concept quickly decreasing in relevance in today's environments. Unfortunately, when you have thousands of people working for you that don't know how to computer, you have to take steps to ensure that the data and functionality that they're handling remains protected.
Additionally, a large amount of attack surface exists on the client side, and with these two factors at play you're dealing with a lot of non-trivial trust relationships within your organisation.
Yes, ideally every system would be an island, and everyone who was supposed to operate it could do so securely and competently enough that they'd realise if something was wrong.
Until then, corporate workstations live in a locked down world where all external access is monitored and scrutinised.
I'm a security guy so I obviously have a differing viewpoint, but when it comes to ensuring what data comes in and leaves your environment there's little choice. The ability to analyse outgoing traffic is really a requirement for being able to effectively detect and respond to incidents.
If your job involves idling on Freenode maybe take it up with management?
EDIT: phrasing
Running an internal DNS resolver is actually very cheap, almost every broadband CPE device runs or can run its own DNS proxy resolver.
It's also a great source of information when monitoring egress communication, so I would just make sure you know what you're doing.
Circumventing your companies firewall is not a great idea in the first place.
Additionally, if they have aggressive egress filtering, its likely that the only DNS communication will be via an internal resolver which is going to be monitored - iodine is going to leave a LOT of shit in those logs.
5.8 is still currently in development/snapshot - not for amateur users.
5.7 is the latest official release. 5.8 is due on Nov 1.
And yet the OP was turned down for not being able to invert a binary tree
Your source is a series of salty tweets.
That's not what the interview process is like at all.
They're more interested in how you approach real world issues (the questions I got asked were conceivably real-life issues a company like Google would face with its products). If you can solve that issue by applying efficient and well understood data structures and algorithms, then that indicates you understand the problem space and solutions that may apply.
It's not like they get you in a room and ask you to draw a linked list or a binary tree.
Hardware like that makes me yearn for one with no wireless and a pair of Gigabit Ethernet ports to use as a firewall and server.
Unfortunately, general purpose hardware and operating system needs a fair amount of juice to route and inspect 1gbps of traffic.
Best performance per watt I've found is the Edgerouter Lite but that has dedicated routing acceleration hardware to achieve what it does with the little mips processor it has.
Closest you'll find is Soekris, ALIX or APU for a routing platform. A Beaglebone black makes a nice little box for lightweight serving on its own.
Just use a procmail rule to call gpg on every incoming email before it's stored using your public key, then your client (configured with your private key) can decrypt every email as normal.
If I had to take a guess...
It'd be easier to carefully add specific features to a well-designed and secure codebase such as OpenBSD, rather than try and pare down and audit the huge codebase and large amount of features provided by something like FreeBSD.
Yes, root's shell should be one provided by the distribution's base install.
I think the biggest worry is that if you need to do something like boot into single user mode for an emergency recovery, and /usr or /usr/local (with root's shell in it) is on a different or unmountable partition then you will not be able to do anything.
I would assume that's the job of the disk's firmware, manage the physical disk and present a compliant interface to the OS (e.g. IDE, SCSI etc...)
What do you mean by "Network effect"?
I don't really see how it applies in this situation. (e.g. you can use uber today and a taxi tomorrow and suffer no loss of value).
Does this involve collusion with the telco? IIRC There's a fair amount of baseband-layer stuff that can be done with SMS from a trusted party.
Considering that XKeyscore was designed to slurp all the things, all the time, this code actually just looks like a very small, tor-specific subset of simple tagging rules.
One would assume that those tags can be used to later analyse the data to pluck out things like "find users from syria who visited tor/tails websites and is related to xyz".