George Mauer

georgemauer.net · Personal blog · on HN since 2016

George Mauer, a software developer, writes about CSV injection, TDD, JavaScript modules, interviews, and debugging stories.

What HN saysHN commenters cite his CSV injection post as the best resource they have found on the issue, including in enterprise settings.
16HN people shared it
7linked it in comments
13stories submitted
746story points
3 months agolast shared
2016people per year2026

Most-shared posts

  1. 1
    Dangers of CSV Injection
    8 people · 648 points · first shared 2017 · 188 comments on HN
  2. 2
    A heck of a wild bug chase
    2 people · 67 points · first shared 2024 · 56 comments on HN
  3. 3
    Take Home Programming Interviews Suck
    2 people · 6 points · first shared 2017 · 2 comments on HN
  4. 4
  5. 5
    Announcing Tech Terms for Memorization
    1 people · 10 points · first shared 2018 · discussion on HN
  6. 6
    Understanding the State of JavaScript Modules
    1 people · 7 points · first shared 2016 · discussion on HN
  7. 7
    Predicting the comeback of XHTML
    1 people · 2 points · first shared 2016 · discussion on HN
  8. 8
    FizzBuzz Tier List
    1 people · 1 points · first shared 2026 · discussion on HN
  9. 9
    Get That Coding Job
    1 people · 1 points · first shared 2023 · discussion on HN
  10. 10
    Dominos v robles
    1 people · first shared 2020

What HN people wrote when they linked it

evnp · 2025-03-26
Anyone with a love of CSV hasn't been asked to deal with CSV-injection prevention in an enterprise setting, without breaking various customer data formats. There's a dearth of good resources about this around the web, this is the best I've come across: https://georgemauer.net/2017/10/07/csv-injection.html
notagoodidea · 2024-06-02
You are in for a whole lot of magical bad ideas :) Also Google Sheets are "vulnerable" to CSV injection [1] too for "here is a link to an evil CSV, import the data yourself" scenario. Honestly if there was a way to Auth (even basic Auth or Bearer) via classic Google Sheets, you could create a monster so easily. [1] http://georgemauer.net/2017/10/07/csv-injection.html
smithkl42 · 2025-11-10
If your attacker controls the data you're exporting to a CSV file, they can take advantage of a memory safety issue in your CSV exporter to execute arbitrary code on your machine. https://georgemauer.net/2017/10/07/csv-injection.html
roberto · 2021-03-30
First, there's no specification. Second, this: http://georgemauer.net/2017/10/07/csv-injection.html
auxym · 2018-10-08
> t's getting to the point where simply opening a Microsoft Office document is roughly the same as opening a random .exe file. This isn't exactly new. In fact it was much worse the late 90s / early 00s, the heyday of windows viruses. There was absolutely no security, opening an excel document automatically meant running arbitrary code that had full system access (via COM, etc). Many viruses spread over email by word and excel documents. At least now, macros execution is disabled by default. Unless you explicitly enable automatic macro execution on all documents, I wouldn't be too worried about opening a documents. Of course, there's the occasional vuln (http://georgemauer.net/2017/10/07/csv-injection.html) but excel isn't exactly the only software with occasional findings of execution vulnerabilities.
bigiain · 2017-11-02
You know you can pop calc with a csv file opened in Excel? from http://georgemauer.net/2017/10/07/csv-injection.html : UserId,BillToDate,ProjectName,Description,DurationMinutes 1,2017-07-25,Test Project,Flipped the jibbet,60 2,2017-07-25,Important Client,"Bop, dop, and giglip", 240 2,2017-07-25,Important Client,"=2+5+cmd|' /C calc'!A0", 240 Yeah - that "=2+5+cmd|' \c calc'!A0" gets Windows to execute code...
sterlind · 2020-12-31
Domino's vs. Robles doesn't say you can't use JS. no court ever ordered Domino's to do anything, afaict. all they did was affirm that Robles was allowed to sue Domino's under the ADA (without deciding whether their site was in fact accessible or not.) See http://georgemauer.net/2019/11/04/dominos-v-robles.html for a good breakdown of the rulings. In particular, Robles wanted the court to order Domino's to make their site WCAG-2.0 compliant. WCAG is completely silent on JavaScript. It's possible that some screen readers don't support JavaScript, but if Domino's site used ARIA tags and complied with WCAG the court would almost certainly consider that accessible (there's no official DoJ guidelines on what constitutes accessibility, so the court and businesses have latitude here.) The ADA is all about reasonable accomodations. Supporting major screen readers is reasonable; supporting all of them clearly isn't. 98% of screen reader users have JS enabled (https://webaim.org/projects/screenreadersurvey4/#javascript), so it's clearly reasonable to provide an accessible webapp.

Keyboard shortcuts

/Search
j kNext / previous blog
EnterOpen selected blog
vVisit the blog site
fFollow / unfollow
lSwitch grid / list view
dSwitch dark mode
g hHome
g pTop posts
g tTopics
g fFollowing
g lLiked
g yHistory
g qFAQ
EscBack / close