181 pointsby boyter6 hours ago21 comments
  • etothet2 hours ago
    Speaking of unique names within AWS, I learned the other day that even after you delete an AWS account, you can’t reuse the root user email addresses (it’s documented, but I wasn’t aware).

    Someone at my org used their main company email address for a root user om an account we just closed and a 2nd company email for our current account. We are past the time period where AWS allows for reverting the account deletion.

    This now means that he isn’t allowed to use SSO via our external IdP because the email address he would use is forever attached to the deleted AWS account root user!

    AWS support was rather terrible in providing help.

    • noahmasur2 hours ago
      You can always use plus-addressing if your email provider supports that. AWS considers plus-addressed root emails to be unique.
      • hallway_monitor2 hours ago
        Doesn’t solve the SSO issue though unless you change your login email
    • jakobobobo2 hours ago
      Good for them. It's amazing how pointless most security is when a 10/10 rating to some commodity communication service's support from a phisher is all it will take.
    • nawgz2 hours ago
      Help me understand why you would delete your AWS account if the company and email address are unchanged - I can’t see the motivation.

      And on the flip side I can easily see why not allowing email addresses to be used again is a reasonable security stance, email addresses are immutable and so limiting them only to one identity seems logical.

      Sounds quite frustrating for this user of course but I guess it sounds a bit silly to me.

      • mixdup6 minutes ago
        >Help me understand why you would delete your AWS account if the company and email address are unchanged - I can’t see the motivation.

        Have you ever worked in a company of any size or complexity before?

        1. Multiple accounts at the same company, spun up by different teams (either different departments, regions, operating divisions, or whatever) and eventually they want to consolidate

        2. Acquisitions: Company A buys Company B, an admin at Company A takes over AWS account for Company B, then they eventually work on consolidating it down to one account

      • etothetan hour ago
        This was a secondary AWS account in use by the company that had been in place for quite some time and that secondary account was just no longer needed. So to consolidate things down, it was deleted. Also at that time, SSO wasn't being used for anything with the company - and they were on a completely different email provider.

        I'm not arguing that it was impossible to know the long term outcome here, but it doesn't mean it isn't frustrating. If you've spent any length of time working in AWS, you know that documentation can be difficult to find and parse.

        I can certainly understand why the policy exists. What I think should be possible is in these situations to provide proof of ownership of the old email address so it can be released and reused somehow.

      • zenopraxan hour ago
        > email addresses are immutable

        1. Use "admin@domain.com"

        2. Let the domain registration lapse

        3. Someone else registers the domain and now can't create an AWS account.

        Rare but not impossible.

        • otterley19 minutes ago
          Sure they can. Use any other email address at domain.com to register.
      • clickety_clackan hour ago
        It’s not hard to imagine a case where maybe there’s 2 offices that had their own separate aws accounts and they closed one.

        AWS has been around for quite a while now. It’s also not impossible to believe that there are companies out there that might have moved from aws to gcp or something, and maybe it’s time to move back.

      • dec0dedab0dean hour ago
        what if you stopped using AWS for a while, then came back?
      • naaskingan hour ago
        > And on the flip side I can easily see why not allowing email addresses to be used again is a reasonable security stance, email addresses are immutable and so limiting them only to one identity seems logical.

        If they aren't actually deleting the account in the background and so no longer have a record of that e-mail address, then they must allow re-activation of the account tied to that e-mail address using the sign-up process.

  • vhab5 hours ago
    > For Azure Blob Storage, storage accounts are scoped with an account name and container name, so this is far less of a concern.

    The author probably misunderstood what "account name" is in Azure Storage's context, as it's pretty much the equivalent of S3's bucket name, and is definitely still a large concern.

    A single pool of unique names for storage accounts across all customers has been a very large source of frustration, especially with the really short name limit of only 24 characters.

    I hope Microsoft follows suit and introduces a unique namespace per customer as well.

    • Twirriman hour ago
      S3 was well aware of the pain when I was there ~10 years ago, just considered themselves handcuffed by the decisions made before the idea of a cloud was barely a twinkle in a few people's eyes, and even the idea of this kind of scale of operation wasn't seen as even remotely probable. The namespace issue is one of a whole long list of things S3 engineers wish they could change, including things like HTTP status code behaviour etc.

      I've never really understood S3's determination not to have a v2 API. Yes, the V1 would need to stick around for a long time, but there's ways to encourage a migration, such as having all future value-add on the V2, and maybe eventually doing marginal increases in v1 API costs to cover the dev work involved in maintaining the legacy API. Instead they've just let themselves, and their customers, deal with avoidable pain.

    • iann00364 hours ago
      Author here. Thanks for the call out! I've updated the article with attribution.
    • mirashiian hour ago
      > especially with the really short name limit of only 24 characters.

      And with no meaningful separator characters available! No dashes, underscores, or dots. Numbers and lowercase letters only. At least S3 and GCS allow dashes so you can put a little organization prefix on them or something and not look like complete jibberish.

    • ryanjshaw5 hours ago
      I recall being shocked the first time I used Azure and realizing so many resources aren’t namespaced to account level. Bizarre to me this wasn’t a v1 concern.
      • mwalser2 hours ago
        And the naming restrictions and maximum name lengths are all over the place: https://learn.microsoft.com/en-us/azure/azure-resource-manag...

        Storage accounts are one of the worst offenders here. I would really like to know what kind of internal shenanigans are going on there that prevent dashes to be used within storage account names.

        • xmcqdpt22 hours ago
          I wonder if it's related to the fact that Windows as such weird rules about allowed file names. Like not directly obviously, more like culturally inside microsoft.
          • mixdup3 minutes ago
            I would not dismiss something like that directly being the cause. Not the reason you can't name a file "CON" on Windows, but it's very likely some weird ass thing they were stringing together with Windows Server and Hyper-V and SMB backed them into the corner we're all in now
          • throwaway1737382 hours ago
            I’m pretty sure Azure was built out with Hyper-V, which was built into the Windows kernel. So everything that relied on virtualization would’ve had bizarre case insensitivity and naming rules.

            I’ve lost track of servers in Azure because the name suddenly changed to all uppercase ave their search is case sensitive but whatever back-end isn’t.

  • josephg4 hours ago
    Sometimes I wonder if package names, bucket names, github account names and so on should use a naming scheme like discord. Eg, @sometag-xxxx where xxxx is a random 4 digit code. Its sort of a middleground between UUID account names and completely human generated names.

    This approach goes a long way toward democratizing the name space, since nobody can "own" the tag prefix. (10000 people can all share it). This can also be used to prevent squatting and reuse attacks - just burn the full account name if the corresponding user account is ever shut down. And it prevents early users from being able to snap up all the good names.

    • jorams4 hours ago
      Notably Discord stopped using that format two years ago, moving to globally unique usernames.

      Their stated reason[1] for doing so being:

      > This lets you have the same username as someone else as long as you have different discriminators or different case letters. However, this also means you have to remember a set of 4-digit numbers and account for case sensitivity to connect with your friends.

      [1]: https://support.discord.com/hc/en-us/articles/12620128861463...

      • shadowfiend2 hours ago
        The actual reason here, implied but not stated outright in that one, is that Discord being a public platform, having only numbers to discriminate between users makes it extra-trivial to impersonate someone else. Obviously you can still do some of this with unique usernames (you see slight misspellings, adding harder-to-see characters like periods, etc, as strategies), but these are more complex to execute on at scale and easier to block once and reduce the impact, vs being able to use ~arbitrarily many post-username numbers.
      • juliangmp3 hours ago
        It was honestly a downgrade i ended up just putting the 4 digits I had before at the end of my username cause surprise the name was taken immediately
        • ffsm83 hours ago
          I haven't logged in since . I wonder if they'll delete my account eventually - as I essentially don't have a username because of that
          • joramsan hour ago
            Your account has almost certainly been assigned a new username already. From the same link:

            > Starting March 4, 2024, Discord will begin assigning new usernames to users who have not chosen one themselves. If your username still has a discriminator (username*#0000*), Discord will begin assigning you a new, unique username as soon as March 4, 2024. We will try to assign you a unique username that is similar to your current username.

          • embedding-shapean hour ago
            > I wonder if they'll delete my account eventually

            Just some days ago I received warning from Discord that they'll delete my account since I haven't logged in for two years.

            > Your Discord account has been inactive for over 2 years, and is scheduled to be deleted on $DATE. But don’t worry! Dust off the cobwebs and prevent your account from being deleted just by logging in.

      • thaumasiotes3 hours ago
        The stated reason is obviously not able to justify the change; either they have an internal reason they're not willing to admit to, or someone at Discord just went crazy.

        Imagine trying to connect with your friends... by telephone.

    • fc417fc8023 hours ago
      IMO a better general solution is UUIDs and a petname system, at least as far as chat apps are concerned.

      For buckets I thought easy to use names was a key feature in most cases. Otherwise why not assign randomly generated single use names? But now that they're adding a namespace that incorporates the account name - an unwieldy numeric ID - I don't understand.

      In the case of buckets isn't it better to use your own domain anyway?

    • rithdmc4 hours ago
      I like it for buckets, but adding a four digit code won't help with the package hijacking side of things - in fact might just introduce more typo/hijack potential. It'll just be four more characters for people to typo.
    • donmcronald4 hours ago
      I just want to be able to use a verified domain; @example.com everywhere.
      • Cthulhu_4 hours ago
        That still has "squatting" risks as described in the original article though, domains expire and / or can be taken over.
        • fc417fc8023 hours ago
          But you already have a domain for whatever you're doing so presumably that's going to be a threat either way.

          For particularly high risk activities if circumstances permit you can sidestep the entire issue by adding a layer of verification using a preshared public key. As an arbitrary example, on android installing an app with the same name but different signing key won't work. It essentially implements a TOFU model to verify the developer.

    • brnt33 minutes ago
      The .NL gTLD used to work like that for personal registrations (ie individuals without a business registration). $name.NNN.nl where you were allowed to choose the number.

      It won't surprise you the scheme never caught on and has been decommissioned (you can now register any available domain as an individual as well). The difference is probably few people use a personal TLD, but many use a name on some social media.

  • iknownothow4 hours ago
    Thank you author Ian Mckay! This is one of those good hygiene conventions that save time by not having to think/worry each time buckets are named. As pointed out in the article, AWS seems to have made this part of their official naming conventions [1].

    I'm excited for IaC code libraries like Terraform to incorporate this as their default behavior soon! The default behavior of Terraform and co is already to add a random hash suffix to the end of the bucket name to prevent such errors. This becoming standard practice in itself has saved me days in not having to convince others to use such strategies prior to automation.

    [1] https://aws.amazon.com/blogs/aws/introducing-account-regiona...

  • ian_d2 hours ago
    The _really_ fun bucket squatting attacks are when the cloud providers themselves use deterministic names for "scratch space" buckets. There was a good DC talk about it at DC32 for AWS, although actual squatting was tough because there was a hash they researchers couldn't reverse (but was consistent for a given account?): https://www.youtube.com/watch?v=m9QVfYVJ7R8

    GCP, however, has does this to itself multiple times because they rely so heavily on project-id, most recently just this February: https://www.sentinelone.com/vulnerability-database/cve-2026-...

  • CafeRaceran hour ago
    While I understand where it's coming from I always had something like <bucket_tag>-<9_random_\d\w>
  • bulbar3 hours ago
    A name shouldn't be the same as the thing it names.

    When a name becomes free and somebody else uses it, it points to another thing. What that means for consumers of the name depends on the context, most likely it means not to use it. If you yourself reassign the name you can decide that the new thing will be considered to be identical to the old thing.

  • PunchyHamsteran hour ago
    decision to make bucket (and not bucket + account id surrogate) a sole key for access was one of most annoying mistakes in S3 design
  • amne35 minutes ago
    I hope nobody wanted "ecommerce-admin". sorry
  • calmworm5 hours ago
    That took a decade to resolve? Surprising, but hindsight is 20/20 I guess.
    • icedchai31 minutes ago
      Two. S3 has been around since 2006!
  • alemwjsl4 hours ago
    I take it advertising your account id isn't a security risk?
    • otterley6 minutes ago
      AWS does not consider it one.

      “While account IDs, like any identifying information, should be used and shared carefully, they are not considered secret, sensitive, or confidential information.” https://docs.aws.amazon.com/accounts/latest/reference/manage...

    • an hour ago
      undefined
    • Cthulhu_4 hours ago
      Armchair opinion, but shouldn't be too bad - it's identification, not authentication, just like your e-mail address is.

      But probably best to not advertise it too much.

    • aduwah4 hours ago
      It is not hygienic, but with only the account-id you are fine. In the IAM rules the attacker can always just use a * on their end, so it does not make a difference. You have to be conscious to set proper rules for your (owner) end tho.
  • ClaudeFixer3 hours ago
    Good riddance. The number of production deploys I've seen pointing at bucket names that could've been claimed by anyone was wild. Glad this is finally getting closed off at the platform level instead of relying on everyone to not make the mistake.
  • INTPenis5 hours ago
    I started treating long random bucketnames as secrets years ago. Ever since I noticed hackers were discovering buckets online with secrets and healthcare info.

    This is where IaC shines.

    • 8organicbits2 hours ago
      ~As far as I know, bucket names are public via certificate transparency logs.~ There are tools for collecting those names. Besides you'd leak the subdomain to (typically) unencrypted DNS when you do a lookup and maybe via SNI.

      Edit: crossout incorrect info

      • BCM432 hours ago
        I'm pretty sure buckets use star certs and thus the individual bucket names won't be in the transparency logs.
        • 8organicbitsan hour ago
          Ah you're right, they are always wildcard certs. I think I was mis-remembering https://news.ycombinator.com/item?id=15826906, which guesses names based on CT logs.

          In either case, the subdomain you use in DNS requests are not private. Attackers can collect those from passive DNS logs or in other ways.

      • embedding-shapean hour ago
        > Besides you'd leak the subdomain to (typically) unencrypted DNS when you do a lookup and maybe via SNI.

        "Leak" is maybe a bit over-exaggerated, although if someone MitM'd you they definitely be able to see it. But "leak" makes it seem like it's broadcasted somehow, which obviously it isn't.

        • 8organicbitsan hour ago
          No man-in-the-middle is needed, DNS queries are often collected into large datasets which can be analyzed by threat hunters or attackers. Check out passive DNS https://www.spamhaus.com/resource-center/what-is-passive-dns...

          You'd need to check the privacy policy of your DNS provider to know if they share the data with anyone else. I've commonly seen source IP address consider as PII, but not the content of the query. Cloudflare's DNS, for example, shares queries with APNIC for research purposes. https://developers.cloudflare.com/1.1.1.1/privacy/public-dns... Other providers share much more broadly.

          • embedding-shapean hour ago
            > No man-in-the-middle is needed [...] Check out passive DNS

            How does one execute this "passive DNS" without quite literally being on the receiving end, or at least sitting in-between the sending and receiving end? You're quite literally describing what I'm saying, which makes it less of a "leak" and more like "others might collect your data, even your ISP", which I'd say would be accurate than "your DNS leaks".

            • 8organicbitsan hour ago
              There's a lot of online documentation about passive DNS. Here's one example

              > Passive DNS is a historical database of how domains have resolved to IP addresses over time, collected from recursive DNS servers around the world. It has been an industry-standard tool for more than a decade.

              > Spamhaus’ Passive DNS cluster handles more than 200 million DNS records per hour and stores hundreds of billions of records per month, providing you with access to a vast lake of threat intelligence data.

              https://www.spamhaus.com/resource-center/what-is-passive-dns...

    • XorNot4 hours ago
      I just started using hashes for names. The deployment tooling knows the "real" name. The actual deployment hash registers a salt+hash of that name to produce a pseudo-random string name.
    • Galanwe4 hours ago
      This is all good and we'll on the IaC side,yes. But at the end of the day, buckets are also user facing resources, and nobody likes random directory / bucket names.
      • INTPenis2 hours ago
        That's a contradiction, a bucket name being treated as a secret in IaC, while being a user facing resource. So no, they're not user facing resources.

        If anyone wants them to be user facing resources, then treat them as such, and ensure they're secure, and don't store sensitive info on them. Otherwise, put a service infront of them, and have the user go through it.

        The S3 protocol was meant to make the lives of programmers easier, not end users.

      • amluto4 hours ago
        It would be nice if the other end of this could be addressed: a configurable policy to limit resolution of bucket names within an account namespace. Ideally, if someone doesn’t have permission to resolve a bucket name, they shouldn’t even be able to detect whether it exists.
  • thih95 hours ago
    > If you wish to protect your existing buckets, you’ll need to create new buckets with the namespace pattern and migrate your data to those buckets.

    My pet conspiracy theory: this article was written by bucket squatters who want to claim old bucket names after AI agents read this and blindly follow.

  • lsaferite2 hours ago
    I mean, why isn't this just the mandatory default going forward? Globally shared, unique bucket names always struck me as a horrible idea.
  • Aardwolf5 hours ago
    Why all that stuff with namespaces when they could just not allow name reuse?
    • hrmtst938372 hours ago
      If you block name reuse globally, you introduce a new attack surface: permanent denial by squatting on retired names. Companies mess up names all the time from typos, failed rollouts, or legal issues. A one-shot policy locks everyone into their worst error or creates a regulatory mess over who can undo registrations.

      Namespaces are annoying but at least let you reorganize or fix mistakes. If you want to prevent squatting, rate limiting creation and deletion or using a quarantine window is more practical. No recovery path just rewards trolls and messes with anyone whose processes aren't perfect.

    • orf4 hours ago
      That would be a huge breaking change. Any workload that relies on re-using a bucket name would be broken, and at the scale of S3 that would have a non-trivial customer impact.

      Not to mention the ergonomics would suck - suddenly your terraform destroy/apply loop breaks if there’s a bucket involved

      • afandian4 hours ago
        Any workload that relies on re-using a bucket name is broken by design. If someone else can get it, then it's Undefined Behaviour. So it's in keeping with the contract for AWS to prevent re-use. Surely?
        • orf3 hours ago
          Think terraform tests, temporary environments, etc. Or anything else: it’s Hyrum's Law.
    • iknownothow4 hours ago
      Potential reasons I can think of for why they don't disallow name reuse:

      a) AWS will need to maintain a database of all historical bucket names to know what to disallow. This is hard per region and even harder globally. Its easier to know what is currently in use rather know what has been used historically.

      b) Even if they maintained a database of all historically used bucket names, then the latency to query if something exists in it may be large enough to be annoying during bucket creation process. Knowing AWS, they'll charge you for every 1000 requests for "checking if bucket name exists" :p

      c) AWS builds many of its own services on S3 (as indicated in the article) and I can imagine there may be many of their internal services that just rely on existing behaviour i.e. allowing for re-creating the same bucket name.

      • dwedge4 hours ago
        I can't accept a) or b). They already need to keep a database of all existing bucket names globally, and they already need to check this on bucket creation. Adding a flag on deleted doesn't seem like a big loss.

        As for c), I assume it's not just AWS relying on this behaviour. https://xkcd.com/1172/

    • JoBrad2 hours ago
      I think a better policy would be to disallow bucket names that follow the account regional namespace convention, but don’t match the account id indicated in the name.
    • 5 hours ago
      undefined
    • CodesInChaos4 hours ago
      I'd allow re-use, but only by the original account. Not being able to re-create a bucket after deleting it would be annoying.

      I think that's an important defense that AWS should implement for existing buckets, to complement account scoped bucket.

      • wiether3 hours ago
        Then they should allow bucket ownership transfer...
  • perunamies2 hours ago
    peruna.fi
  • sriramgonella4 hours ago
    [dead]
  • shablulman5 hours ago
    [dead]
  • ChrisMarshallNY5 hours ago
    [flagged]
    • iknownothow4 hours ago
      I'd ask politely to refrain from such comments :)

      This is not me criticising you. I totally understand the urge to say it. We're all thinking the thing you're thinking of. It takes effort not to give into it ;)

      The reason I personally would refrain from making such comments is that they have the potential to end up as highest ranked comment. That would be a shame. Topic of S3 bucketsquatting is rather important and very interesting.

      • AznHisoka4 hours ago
        He is just comment squatting :)
      • ramon1564 hours ago
        You did not really give a reason to refrain from making a joke. Don't take yourself too serious
      • Hamuko4 hours ago
        >We're all thinking the thing you're thinking of.

        I wasn't but I sure am now.

    • DonHopkins5 hours ago
      It sounds like a sensitive subject, very delicate, and of no concern to law enforcement, for private videos of an artistic nature.

      https://www.youtube.com/watch?v=KaQ-s_P5mwM

  • lijok5 hours ago
    Huh? Hash your bucket names
    • why_only_155 hours ago
      if your bucket name is ever exposed and you later delete it, then this doesn't help you.
      • lijok3 hours ago
        The entire article talks about “guessing” the bucket name as being the attack enabler, not the leaking of it. What does the landscape look like once you start doing the basics like hashing your bucket names? Is this still a problem worth engineering for?
    • Maxion5 hours ago
      I don't think that'd prevent this attack vector.
      • alemwjsl4 hours ago
        Ok; salt, and then hash your bucket names
        • xxs3 hours ago
          that doesn't help either. 'Salt' is public and usually different/unique per entry/name.

          If you mean to use a "secret" prefix (i.e. pepper) then, that would generate effectively globally unique names each time (and unpredictable too) but you can't change the pepper and it's only a matter of time it'd leak.

          • tostian hour ago
            Random pepper. Or just, y'know, randomly generate the effing string. Can't be that hard.
          • lcnPylGDnU4H9OFan hour ago
            If they can't make the bucket before you do then they are not "bucket squatting", and they can't do so for a salted and hashed bucket name without knowing the salt at runtime.

            The public/private distinction seems moot here, too: the salt is a throwaway since you just need the bucket name.

            Even if you do need to keep track of the salt, it should be safe for the attacker to know, at least with respect to this attack, because you already own the bucket which the attacker would otherwise hoard.