WordPress plugin quirk resulted in UK Gov OBR Budget leak [pdf]

https://obr.uk/docs/dlm_uploads/01122025-Investigation-into-November-2025-EFO-publication-error.pdf

by robtaylor • 8 months ago

130 123 8 months ago

kingkool682• 8 months ago

What was the quirk?

cstuder• 8 months ago

A feature known as the Download Monitor plug-in created a webpage with the clear URL which provided a link to the live version, which bypassed the need for authentication. This rendered the protections on the ‘future’ function of WordPress redundant as it bypassed the required authentication needed to gain access to the pre-uploaded document.

WordPress is a nice piece of software, but the plugin situation is getting worse and worse. (Too many pending updates, premium features and constant upselling, selling of plugins to new sketchy owners...)

withinboredom• 8 months ago

The main issue is that there isn't any governance to the plugin store. Once you have a plugin in there, you have free reign to do whatever you want with it. Getting it in there is a PITA though. For example, a library author and I created a plugin, but they wouldn't let me submit it because I wasn't the other author, and they wouldn't let him submit it because he wasn't me. True story.

devnull3• 8 months ago

which provided a link to the live version

Even if that is the case, the backend must validate.

whycome• 8 months ago

My favorite current plugin woe is where it completely changes what it does but keeps the same name and it's all a part of its 'update'

chippiewill2• 8 months ago

WordPress is a nice piece of software, but the plugin situation is getting worse and worse

The plugin situation is a mess largely because Wordpress isn't a nice piece of software.

It's popular, and functionally it's great, but the codebase is really showing its age. Wordpress has never properly rearchitected because it would break plugins on a scale that would endanger its dominance.

kstrauser2• 8 months ago

To an outsider, its entire plugin ecosystem is so odd. Like the conversation about “nulled” plugins, where someone removes license-checking code from GPL-licensed plugins and then redistributes them, and whether that’s moral, or even legal, which of course it is, because that’s the entire point of the GPL.

merrvk2• 8 months ago

Why are government organisations which handle sensitive information using Wordpress?

jamesbelchamber3• 8 months ago

There's not anything obviously wrong with using WordPress for publishing documents like this - they are meant to be public after all.

The problem was essentially that, through a misconfiguration, they published it early.

bell-cot• 8 months ago

In huge org's, doing computer-related stuff the "right" way often involves so many meetings, sign-offs, and miles of red tape that your grandchildren would die of old age before anything actually got done.

Vs. if you just let Will and Pete do it in WordPress (or on Facebook, or such) then needed tasks might actually be accomplished.

tolerance2• 8 months ago

This is a reasonable question. I mean yeah it’s supposed to be made public anyway, but evidently there is a non-trivial amount of interest invested in its contents by people who don’t usually qualify when we think of “the public”. Otherwise what would be the big deal?

My guess is that the team responsible for this didn’t anticipate or at worst were not informed of its value to particular groups of people, at least not to a degree that would’ve warranted extra security measures.

tantalor2• 8 months ago

It's not sensitive information. It's public information.

merrvk2• 8 months ago

Before it’s been released I would consider it sensitive for many reasons.

Roscius• 8 months ago

"On the reason for the early publication, Prof Martin said it was related to the software the OBR chose to publish to its website, which was more suitable for a small or medium company than a major publication of critical market-sensitive data."

Using WordPress plugins (with the exception of a limited sub-set) is like chewing gum you find on the sidewalk.

A technical oversight fail at multiple levels.

RobotToaster3• 8 months ago

There's a UK government policy to try and use open source, they even have a github profile https://github.com/alphagov

glenjamin• 8 months ago

There's a couple of passing mentions of Download Monitor, but also the timeline strongly implies that a specific source was simply guessing the URL of the PDF long before it was uploaded

I'm not clear from the doc which of these scenarios is what they're calling the "leak"

shawabawa3• 8 months ago

but also the timeline strongly implies that a specific source was simply guessing the URL of the PDF long before it was uploaded

A bunch of people were scraping commonly used urls based on previous OBR reports, in order to report as soon as it was live, as it common with all things of this kind

The mistake was that the URL should have been obfuscated, and only changed to the "clear" URL at publish time, but a plugin was bypassing that and aliasing the "clear" URL to the obfuscated one

physicsguy4• 8 months ago

in order to report as soon as it was live

We don't actually know that, it's just that the report did hit Reuters pretty swiftly.

longwave• 8 months ago

It sounds like a combination of the Download Monitor plugin plus a misconfiguration at the web server level resulted in the file being publicly accessible at that URL when the developers thought it would remain private until deliberately published.

dazc• 8 months ago

https://obr.uk/docs/dlm_uploads/OBR_Economic_and_fiscal_outl... 5.pdf

Not hard to guess really. Wouldn't they know this was likely and simply choose a less obvious file name?

jonplackett3• 8 months ago

Turn out, no. Not they would not.

blurayfin• 8 months ago

https://www.pluginscore.com/plugins/download-monitor

jamesbelchamber3• 8 months ago

For those of you not closely following UK politics: the Office for Budget Responsibility (OBR) mistakenly published their Economic and Fiscal Outlook (EFO) document 40 minutes early, pre-empting the announcements by the Chancellor.

This is being treated as an incredibly big deal here: https://www.bbc.co.uk/news/articles/cd74v35p77jo

hdgvhicv4• 8 months ago

In the popular press it’s been sidelined because it would distract from the continuous attacks on the chancellor

louthy2• 8 months ago

Yes, it’s getting quite ridiculous now. Labour, for sure, have not done themselves any favours in their first 18 months in charge, but the level of attack and vitriol is exceptional and beyond any reasonable level.

It makes me wonder what exactly is driving this.

tantalor2• 8 months ago

which it blamed on a "technical error"

It's not a technical error at all!

Technical errors are faults caused by technology, like a software or hardware bug. That's not what happened here. WordPress behaved exactly as it was supposed to.

The true cause is revealed later in the article,

staff thought they had applied safeguards to prevent early publication, there were two errors in the way in which they were set up

The problem was the staff. It's a human error.

graemep3• 8 months ago

A well designed system would reduce the risk of human error.

Given the importance of keeping this information confidential, they really ought to have a custom system for releasing it, not just configuring a third party Wordpress plugin.

chriswarbo• 8 months ago

I don't think that's a worthwhile distinction. All software bugs are human errors, since the machine is correctly following the human programmer's incorrect instructions; whether that's at the level of assembly instructing the CPU; or a higher level like Wordpress instructing the PHP interpreter; or an even higher level of a document hosting solution instructing Wordpress.

_dain_• 8 months ago

"Human error" is not the end of an explanation, it's the start of an explanation.

As an industry we should know this by now. Defaults matter.

https://www.humanfactors.lth.se/fileadmin/lusa/Sidney_Dekker...

jpfromlondon• 8 months ago

I like to think they're just looking out for us after the government implied the OBR was untrustworthy.

M2Ys4U• 8 months ago

During that period, it was accessed 43 times by 32 unique IP addresses

I find this an implausibly low number. It was all over Bluesky, X etc., not to mention journo Signal and WhatsApp groups.

jamesbelchamber3• 8 months ago

Possibly copies of the document rather than the original URL?

logicchains• 8 months ago

Maybe it was cached somewhere and most people were hitting the cache?

m4tthumphrey• 8 months ago

Either that number was wrong like you say OR (and I am unfamiliar with Bluesky) the URL is loaded via Bluesky's browser (like X) and therefore Bluesky's own server IP was used (instead of the user's).

Edit: Or (and more likely) cached/copies of the original.

reddalo• 8 months ago

I feel like those 32 unique IP addresses may very well be Cloudflare or CloudFront ones.

ZoneZealot• 8 months ago

I agree, and I also am familiar with how WP Engine's 'GES' (global edge security) works. obr.uk points to two IP addresses held in the name of WP Engine, but they're actually BYOIP with Cloudflare. Cloudflare act as a caching layer, DDOS mitigation and WAF.

Note that GES works a bit different to traditional Cloudflare implementations, HTML requests are basically passed through to the WP Engine NGINX reverse proxy server that's in front of the WordPress site (as opposed to being heavily cached with Cloudflare). Static assets, like a PDF - would indeed be cached with GES.

fabian2k2• 8 months ago

The available mitigation is at server level and prevents access to download or file storage directories directly. If configured properly, this will block access to the clear URL and return a ‘forbidden’ message. This is the second contributory configuration error – the server was not configured in this way so there was nothing to stop access to the clear URL bypassing protections against pre-publication access

That's the main flaw. Wordpress was configured to allow direct access to file, so they did not go through the authentication system. My experience is with Drupal (and a decade or more out of date), but it sounds like this behaves very similar. And this is a giant footgun, the system doesn't behave the way normal people expect if you allow unauthenticated access to files (if you know the URL). I don't understand why you would configure it this way today.

I would also assume that the upload happened via Wordpress, and not someone manually uploading files via FTP/SFTP or something like that. And in that case it would be entirely non-obvious to users that attaching a file to an unpublished document would put it in a place where it is potentially publicly accessible.

snowwrestler• 8 months ago

Since at least Drupal 7, the core CMS has included the concept of “private files.” The files are stored in a directory that is not served publicly by the web server. Instead the CMS generates a proxy URL for each file, which is handled by the CMS like a page URL before serving the file by streaming it through PHP. So: it’s a heavier load on the server, but you get full permission management by the CMS.

Wordpress does not have this in core—no surprise. I was surprised to find that it’s not even available as a community plugin. I had to pay a developer to write a custom plugin when building a members-only website in Wordpress.

Some folks downplayed the risk of someone finding and directly accessing the file URL if it wasn’t referenced on a public page. It’s crazy to see it created a national government incident in the UK.

Y-bar• 8 months ago

I was surprised to find that it’s not even available as a community plugin.

I found this one https://wordpress.org/plugins/prevent-direct-access/

fabian2k2• 8 months ago

That's even worse than I thought. I assumed it is a setting like in Drupal.

To me it really doesn't make any sense to have that kind of giant hole in your permissions system from the start.

londons_explore• 8 months ago

It is the worst failure in the 15-year history of the OBR

I'm not sure publishing some information 3 hours early was really their biggest failure in 15 years...

Especially when much of the info was already public because hundreds of civil servants involved in making these decisions told their family members who told the press...

afavour• 8 months ago

It's still a failure in principle. The effects of this particular instance of the failure were minimal but it was still an accidental leak of (at the time) private information. They just got lucky.

blibble4• 8 months ago

The effects of this particular instance of the failure were minimal

the effects are not minimal

if you're crooked: getting this sort of information early is potentially extremely lucrative

(why crooked? because trading on UPSI is illegal)

almostkindatech2• 8 months ago

If by 'much of the info' you mean policy changes, those are deliberately leaked by the politicians, not civil servants or their family members. They do this to test reactions and frame the debate.

TheRealPomax• 8 months ago

I think you mean "no one got paid to vet the wordpress plugins"

gnfargbl• 8 months ago

The real kicker is in point 1.13:

website activity logs show the earliest request on the server for the URL https://obr.uk/docs/dlm_uploads/OBR_Economic_and_fiscal_outl.... This request was unsuccessful, as the document had not been uploaded yet. Between this time and 11:30, a total of 44 unsuccessful requests to this URL were made from seven unique IP addresses.

In other words, someone was guessing the correct staging URL before the OBR had even uploaded the file to the staging area. This suggests that the downloader knew that the OBR was going to make this mistake, and they were polling the server waiting for the file to appear.

The report acknowledges this at 2.11:

In the course of reviewing last week’s events, it has become clear that the OBR publication process was essentially technically unchanged from EFOs in the recent past. This gives rise to the question as to whether the problem was a pre-existing one that had gone unnoticed.

rahimnathwani• 8 months ago

The report also says a previous report was also accessed 30 mins early.

philipwhiuk2• 8 months ago

In other words, someone was guessing the correct staging URL before the OBR had even uploaded the file to the staging area. This suggests that the downloader knew that the OBR was going to make this mistake, and they were polling the server waiting for the file to appear.

The URLS are predictable. Hedge-funds would want to get the file as soon as it would be available - I imagine someone set up a cron-job to try the URL every few minutes.

kypro• 8 months ago

This is so incompetent.

Given the market significance of the report it's damn obvious that this would happen. They should have assumed that security via obscurity was simply not enough, and the OBR should have been taking active steps to ensure the data was only available at the correct time.

Hedge-funds would want to get the file as soon as it would be available - I imagine someone set up a cron-job to try the URL every few minutes.

It's not even just hedge-funds that do this. This is something individual traders do frequently. This practise is common place because a small edge like this with the right strategy is all you need to make serious profits.

blitzar2• 8 months ago

I used to do this for BOE / Fed minutes, company earnings etc on the off chance they published it before the official release time.

2025-Q1-earnings.pdf - smash it every 5 seconds - rarely worked out, generally a few seconds head start at best. By the time you pull up the pdf and parse the number from it the number was on the wires anyway. Very occasionally you get a better result however.

lesuorac2• 8 months ago

This suggests that the downloader knew that the OBR was going to make this mistake, and they were polling the server waiting for the file to appear.

I think most of the tech world heard about the Nobel Peace Prize award so it doesn't seem that suspicious to me that somebody would just poll urls.

Especially since before the peace prize there have been issues with people polling US economic data.

My point is strictly, knowledge that they should poll a url is not evidence of insider activity.

accoil• 8 months ago

How does the Nobel Peace Prize figure into this? I seem to be on the other side that didn't hear about the award. Which is not surprising as I don't follow it, but also I haven't worked out query terms to connect it with OBR.

kristianc2• 8 months ago

Part of this is a product of the UK's political culture where expenses for stuff like this are ruthlessly scrutinised from within and without.

The idea of the site hosting such an important document running independently on WordPress, being maintained by a single external developer and a tiny in-house team would seem really strange to many other countries.

Everyone is so terrified of headlines like "OBR spends £2m upgrading website" that you get stuff like this.

toyg3• 8 months ago

It's not an easy call. Sometimes, one or two dedicated and competent people can vastly outperform large and bureaucratic consulting firms, for a fraction of the price. And sometimes, somebody's cousin "who knows that internet stuff" is trousering inflated rates at the taxpayer's expense, while credentialed and competent professionals are shut out from old boys' networks. One rule does not fit all.

dboreham2• 8 months ago

Quirk? Surely a bug?

philipwhiuk2• 8 months ago

It's not a bug if it's the expected behaviour

bitlevel• 8 months ago

It's not a bug - it's a feature.

tolerance2• 8 months ago

So is the significance of this news based on what could have leaked if the document was not intended for the public? [1]

Or is the significance of this news based on the advantages that players on the market who caught hold of it early will have? Is it only important to civilians relative to their ability to question who may be benefitting from the 40 minute head start that these players might have gained or (for the conspiracy-minded) been handed through nefarious means?

[1]: Which would lead me to ask why would it belong on a platform typically intended for publishing things in public.

macleginn• 8 months ago

Interestingly, the public discourse in the UK (at least what I have observed, and it was hard not to observe a lot in the last several days) does not focus much (if at all) on the insider trading angle. It's mostly that the chancellor has this important duty to first announce the new budget beofre the Parliament, and if this course of events gets distorted this is very bad for the proper procedure. Now, the sole purpose of OBR is to ensure the proper procedure, so very silly (or "damning") of them to make such a mistake.

At the same time, almost every piece of legislation in recent years has been relentlessly leaked and taken apart way before the official announcement in parliament, so this is a wee bit ridiculous.

jonplackett3• 8 months ago

It’s just about incompetence really. The budget is meant to be highly secret. And they accidentally published their report early. Which would let some people benefit from in financially, but it’s also just very embarrassing for a government. Sometimes budgets contain info that is more valuable than this.

varispeed• 8 months ago

They didn’t suffer a breach; they published a market-moving PDF early because they put it on a public WordPress server at a predictable URL with no access control, then acted shocked when someone typed it into a browser. The report dresses this up in solemn language about “pre-publication facilities” and “configuration errors”, but the reality is negligent basics: no authentication, no server-level blocking, blind faith in a plugin they didn’t understand, and not one person running the obvious test of guessing the URL before go-live. Their claim of “independence” just meant running the most sensitive part of their job on an underpowered, misconfigured website while assuming everything else would magically hold together. This wasn’t a cyber incident. It was institutional incompetence wearing a suit.

jonplackett3• 8 months ago

But but but they ‘have a limited budget’ (repeated multiple times for effect in the article)

blitzar2• 8 months ago

~£4mil budget and 50 staff

chuckreynolds• 8 months ago

"WordPress plugin quirk" AKA human error (as usual).

tonyedgecombe• 8 months ago

Yes, the human error was using WordPress.

petit_robert• 8 months ago

I had to laugh out loud at this (by myself).

The amount of requests I get on my servers for WP related files is insane

rvz• 8 months ago

What the f____?

The contents of market sensitive information critical to the finances of the entire country is behind stored on a damn vulnerable Wordpress server.

It's not even accidental access or a premature push of the button to release the document, but the site was regularly breached over and over and over again likely for insider trading ahead of the budget.

Might as well store the UK nuclear key codes on a large bright yellow Post-It note in Piccadilly Circus.

What a complete joke on the lack of basic security.

pentagrama• 8 months ago

Ok, it was the Download Monitor plugin.

But I still have a few questions. What is WordPress’s default behavior? Does it prevent files uploaded to the media library from having public URLs? Are they only public once they are inserted into a published post? Images make sense because they are embedded, but what about a PDF linked inside a post? My understanding is that media files become publicly accessible as soon as they are uploaded, as long as someone knows or guesses the URL. I mean, the leak could have happened even without the plugin?

kingkool682• 8 months ago

Correct. Files uploaded get stored in the wp-content/uploads folder and are public.

froobius• 8 months ago

And the news just now is that the chair of the OBR has resigned because of this [1]

[1] https://www.bbc.co.uk/news/live/cly147rky81t

almostkindatech2• 8 months ago

And now the chair of the OBR has had to resign over it https://www.theguardian.com/politics/live/2025/dec/01/keir-s...

hombre_fatal• 8 months ago

This doesn't seem to have much to do with Wordpress or its plugin ecosystem but rather an oversight since the behavior itself isn't necessarily a bug. I think the "well yeah, why would you use Wordpress?" comments kinda miss that.

It's a ubiquitous practice to serve file uploads from a place outside of webserver middleware. This happens pretty much any time an upload permalink is on a different domain or subdomain, and it's standard on probably 90% of platforms.

Discord and Twitter file upload urls would be an example off the top of my head.

It would have been prevented if the public url used a random UUID, for example. But that's also not the behavior users necessarily want for most uploads.

hexbin010• 8 months ago

Should have used S3 and a datetime-based access policy. Eg

  {
    "Version": "2012-10-17",
    "Statement": [
      {
        "Sid": "Statement1",
        "Effect": "Allow",
        "Action": [
          "s3:GetObject"
        ],
        "Resource": "arn:aws:s3:::obr-leaky-bucket/myfirst.pdf",
        "Condition": {
          "DateGreaterThan": {
            "aws:CurrentTime": "2025-11-26T12:30:00"
          }
        }
       }
    ]
  }

cocainemonster• 8 months ago

should've dug a hole for tomatoes with an excavator

saaaaaam• 8 months ago

The log of events in that document is absolutely hilarious/pitiful. It’s like something lifted directly from an episode of In The Thick Of It.

A honest-to-goodness proper fucking omnishambles.

11:52 - senior OBR and Treasury officials telephoned each other to discuss the breach. These Treasury officials made OBR staff aware of the URL leading to the PDF of the EFO that was accessible.

11:53 - OBR staff and the web developer attempted to pull the PDF from the website, and also to pull the entire website (e.g. via password protection), but struggled to do so initially due to the website being overloaded with traffic.

11:58 - an email was received to the OBR press inbox from a Reuters journalist confirming that Reuters had published details of the EFO and asking for comment.

12:07 - the EFO PDF was renamed by the web developer.

12:07 - the EFO PDF appeared on the Internet Archive. This means it was, at that precise time, visible entirely generally on the open internet via search engines. It is assumed that this happened very briefly in the rush to remove it.

khaki54• 8 months ago

If you've ever looked at the admin panel of even a minor league, single page Wordpress site you'd probably recognize it as a major risk for any organization instantly. So many of the plugins look like spaghetti, with most you're trusting some random name to not be malicious. Unsurprisingly there are 60,000 CVE related to WP. I get that we all use a dozen node packages that we can't reasonably verify, but WP seems so much more wild west than that. I guess i's fine if you are a low value target, but a commercial CMS is not terribly expensive, and should be mandatory for any government org.

iamcreasy• 8 months ago

11:53 – OBR staff and the web developer attempted to pull the PDF from the website,and also to pull the entire website (e.g. via password protection), but struggled to doso initially due to the website being overloaded with traffic

This one is painful to read. What was their option here? Calling WP Engine to take it offline?

WordPress plugin quirk resulted in UK Gov OBR Budget leak [pdf]

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