RCE Vulnerability in QBittorrent – Sharp Security
RCE Vulnerability in QBittorrent – Sharp Security
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/
If you are running Windows [...]
and
from June 2015 until the present, affecting v3.2.1 through v5.0.0 inclusive. The behaviour does not appear to be replicated for other OS variants
Notably, 5.0.1 was released three days ago. So a fix is available.
The first patched release is version 5.0.1, released 2 days ago.
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 distroThe 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 toContainerization helps, but best to patch asap.
Mitigations
Just use another torrent client. Deluge and Transmission etc do not have this vulnerability.
Was wondering what the takeaway is here. I updated to 5.0.1. Does that fix all these? If not, guess I'll try a different torrent client.
The first patched release is version 5.0.1, released 2 days ago.
yeah, they have other undiscovered vulnerabilities
Is there something we should do in the meantime? I’m not the most savvy individual when it comes to tech on this level.
Not really. This requires a sophisticated attacker. I’d suggest updating soon but I doubt most people are at risk. As always verify downloads before running them and check where you should be getting updates and if you’re sent to a sketchy file host try to find updates from the official website instead.
The biggest risk is MTM interception and replacement of the python executable if you try and use the search tool for the first time. I suppose avoid doing that until you update the client from their website.
Thanks. This makes it a lot clearer.
i kinda wish that some people who post security vulns stop being so vague and cherry-picky sometimes, like you could have written in your post that it only affects windows and it affects only a certain range of versions of the program. would have clearned things up better imo. interesting to know, though.
You should have read the post more carefully. The CVE affects every OS. Just the first shown example is Windows only.
Also, the relevant commits are outlined in the first paragraph. This article is not for the stupid user it's a technical analysis on a few ways to exploit it and for those cases the commits are more relevant than the version. Also saying which versions are affected is not that easy, commits can be backported into an older version by for example the packager.
Will I be OK updating from the Debian repo?
From another poster above, it seems only Windows machines are affected.
i'm wondering the same thing, except i'm using linux mint.. and i'm using the flatpak version and i'm actually kinda paranoid
does anyone know if the flatpak version is affected? i'm actually paranoid right now