I dont know who needs to hear this bit qBittorrent has a nasty vulnerability ( and there are some older ones too)

qBittorrent, on all platforms, did not verify any SSL certificates in its DownloadManager class from 2010 until October 2024. If it failed to verify a cert, it simply logged an error and proceeded.

To be exploitable, this bug requires either MITM access or DNS spoofing attacks, but under those conditions (seen regularly in some countries), impacts are severe.

The primary impact is single-click RCE for Windows builds from 2015 onward, when prompted to update python the exe is downloaded from a hardcoded URL, executed, and then deleted afterwards.

The secondary impact for all platforms is the update RSS feed can be poisoned with malicious update URLs which the user will open in their browser if they accept the prompt to update. This is browser hijacking and arbitrary exe delivery to a user who would likely trust whatever URL this software sent them to.

The tertiary impact is this means that an older CVE (CVE-2019-13640 https://www.cvedetails.com/cve/CVE-2019-13640/) which allowed remote command execution via shell metacharacters could have been exploited by (government) attackers conducting either MITM or DNS spoofing attacks at the time, instead of only by the author of the feed.

Full write up is here: https://sharpsec.run/rce-vulnerability-in-qbittorrent/

  • Perfect example of a (part of a) security vulnerability being fixed in a commit that doesn’t immediately seem security related and would never be back ported to a stablestale distro

    The code which parses the binary MaxMind database after decompression is well guarded as of 2024 but used to look different, potentially providing more attack surface. There is also an interesting commit where a contributor makes adjustments to the gzip::decompress() function which hints at a stack overflow, as the destination buffer was changed from static allocation on the stack to dynamic allocation on the heap, though it was not exploitable due to checks before it is written to