Security News > 2022 > September > Chrome and Edge fix zero-day security hole – update now!

We'd love to be able to determine, given that the bug relates to the incorrect handling of input data, whether this bug leads to a worrying security outcome such as EoP, short for elevation of privilege, or if it can be abused for a more disastrous result such as full-blown RCE, short for remote code execution.

As a result, modern browsers generally split themselves into numerous separate processes, for example so that each tab is handled in an independent process, thus preventing one runwaway tab from trivially leeching data such as cookies and access tokens from others tabs related to completely different websites.

That's where you need an aptly named inter-process communincation system, or IPC. Any processes that shuffling data between themselves via IPS need to agree on how to construct that data correctly for sending, and how to deconstruct it safely at the other end.

The jargon term for this is serialisation and deserialisation, because you're taking chunks of data, possibly plucked out of content already stored in numerous different areas of memory, and converting those chunks into a structured list of "Here is your very own record of the data items, the types and the values of the stuff you need to know".

Once serialised, the data can then be transmitted to another process - perhaps via a shared block of memory, or over a communication pipe at the operating system level, via a network link, or even tapped out in Morse code for anyone to pick up - in such a way that the receiver can make sense of the data, and unpack it independently, without needing to know anything about the current or future internal state of the sender's process.

In the second example, if process A forgets about the width and height data and sends a full 128 bytes of UTF-8 text instead, then blindly "Decoding" two 32-bit numbers at the end will produce incorrect values, perhaps even dangerously so.

News URL

https://nakedsecurity.sophos.com/2022/09/05/chrome-fixes-zero-day-security-hole-reported-anonymously-update-now/