A customer reported that a recent Windows update broke their ability to type a snowman by using Alt+9731. We explained that the update was not at fault; rather, Alt+9731 was never supposed to produce a snowman at all! But the customer insisted that it used to work.

source: HN

It’s only been in the last couple of years that I’ve begun to dig deep into the inner workings of how terminal emulators, and the applications that run inside of them, really work. I’ve learned that there is a lot of innovation and creative problem solving happening in this space, even though the underlying technology is over half a century old1.

I’ve also found that many people who use terminal based tools (including shells like Bash and editors like Vim) know very little about terminals themselves, or some of the modern features and capabilities they can support.

In this article, we’ll discuss some of the problems that terminal based applications have historically had to deal with (and what the modern solutions are) as well as some features that modern terminal emulators support that you may not be aware of.

source: Dfly

For practical purposes, old source files are not text files. They are binary files, and must be preserved without modification. It is not OK to take an old source file and convert it to UTF-8. For one thing, UTF-8 didn’t even exist in the times of MASM 5.10 and Microsoft C 5.1, of course old tools can’t deal with it!

source: L

I continue to maintain my census of U.S. cases referencing emojis or emoticons. In 2023, I logged 225 such cases (this number will grow a bit due to lags with the electronic databases). The case count continues to grow exponentially. The 2023 count represented a 17% increase over the 2022 count.

It’s one of those anachronisms that is deeply embedded in modern technology. From cloud operator servers to embedded controllers in appliances, there must be uncountable devices that think they are connected to a TTY.

source: Dfly

CVEs in three strange places and the unique problem of safely processing and handling fonts.

Although the previous research focused primarily on memory corruption bugs in font processing, we wondered what other kinds of security issues might occur when handling fonts.

source: HN

In a previous post I went over a vulnerability I discovered in iTerm2 that allowed code execution in the shell by leveraging the output of a command. Today, We’ll focus on the other side of that interaction, the application running underneath the terminal.

This paper reflects work done in late 2022 and 2023 to audit for vulnerabilities in terminal emulators, with a focus on open source software. The results of this work were 10 CVEs against terminal emulators that could result in Remote Code Execution (RCE), in addition various other bugs and hardening opportunities were found. The exact context and severity of these vulnerabilities varied, but some form of code execution was found to be possible on several common terminal emulators across the main client platforms of today.

source: HN

I could, element by element, continue to add support (mostly by making CSS updates for each element to fit in with the rest of my style choices) as I came across specific needs for them, but not one to shy away from an exhaustive exploration, I decided to write this post and attempt to use every element.

A goal of the post, was to avoid delaying other future posts with CSS updates on a previously unused element, but in reality it took a year and a half to make all the updates for just this post! I am using the MDN Web Docs list of HTML elements as a reference which has more than 100 tags divided into a few categories, which I will also use in this post.

source: L

Regex gets a bad reputation for being very complex. That’s fair, but I also think that if you focus on a certain core subset of regex, it’s not that hard. Most of the complexity comes from various “shortcuts” that are hard to remember. If you ignore those, the language itself is fairly small and portable across programming languages.

It’s worth knowing regex because you can get A LOT done in very little code. If I try to replicate what my regex does using normal procedural code, it’s often very verbose, buggy and significantly slower. It often takes hours or days to do better than a couple minutes of writing regex.

source: L

Still, the debugging process we went through here to discover the cause of the problems in the first place is worth sharing from the beginning, as the code in question was particularly bad with plenty of textbook mistakes. Who knows what you might find in your own investigations elsewhere.

Email: https://marc.info/?l=openbsd-tech&m=167734639712745&w=2

source: L

We’d managed to get from ‘some quite strange things are happening to the header, beta banner and buttons’ to ‘text wraps unnecessarily within intrinsically-sized elements when using certain fonts and the inner HTML of the element contains a new line that is not preceded by a space’.

source: HN

Trailing dots on host names in URLs is the gift that keeps on giving. Let me take you through a dwindling story of how the dot is handled differently in different places through the stack of an Internet client. The evil trailing dot.

source: L

Known as right angle with downwards zigzag arrow, angle with down zig-zag arrow, \rangledownzigzagarrow, and ⍼, no one knows what ⍼ is meant to represent or where it originated from. Section 22.7 Technical Symbols from the Unicode Standard on the Miscellaneous Technical block doesn’t say anything about it.

source: L

This research originated when I realized the default text reader on OSX, TextEdit is used to open files with TXT extension by default. On the interface of TextEdit, it looked like you can do basic customization to your text (you can turn text bold, italic, change color etc...), so I was wondering how a TXT file was storing and parsing this information. It seems it uses RTF format instead of TXT if we add customizations to the text.

source: HN

The same JSON document can be parsed with different values across microservices, leading to a variety of potential security risks. If you prefer a hands-on approach, try the labs and when they scare you, come back and read on.

https://github.com/BishopFox/json-interop-vuln-labs/

source: HN

Slides follow Markdown syntax.

And there’s fireworks!

source: HN

Larry Wall posted patch 1.3 to mod.sources on May 8, 1985. A number of versions followed over the years. It’s been a faithful alley for a long, long time. I’ve never had a problem with patch until I embarked on the 2.11BSD restoration project. In going over the logs very carefully, I’ve discovered a bug that bites this effort twice. It’s quite interesting to use 27 year old patches to find this bug while restoring a 29 year old OS...

source: HN

I show how to use heterogeneous lists and traits to implement a type-safe printf in Rust. These mechanisms can ensure that two variadic argument lists share important properties, like the number of format string holes matches the number of printf arguments.

source: HN

The CharUpper function tries to convert the string in place, but if the uppercase and lowercase versions of a character are not the same length, then it panics and does something strange.

Also: https://devblogs.microsoft.com/oldnewthing/20200803-00/?p=104038