CVE-2021-32795 Denial of Service via Steam chat in ArchiSteamFarm
An unauthenticated attacker can crash the ArchiSteamFarm application by sending a crafted Steam chat message, causing a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-32795?
CVE-2021-32795 is a medium-severity denial of service vulnerability in JustArchiNET ArchiSteamFarm, published on 26 Jul 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
ArchiSteamFarm is a C# application with primary purpose of idling Steam cards from multiple accounts simultaneously. In versions prior to 4.3.1.0 a Denial of Service (aka DoS) vulnerability which allows attacker to remotely crash running ASF instance through sending a specifically-crafted Steam chat message exists. The user sending the message does not need to be authorized within the bot or ASF process. The attacker needs to know ASF's `CommandPrefix` in advance, but majority of ASF setups run with an unchanged default value. This attack does not allow attacker to gain any potentially-sensitive information, such as logins or passwords, does not allow to execute arbitrary commands and otherwise exploit the crash further. The issue is patched in ASF V4.3.1.0. The only workaround which guarantees complete protection is running all bots with `OnlineStatus` of `0` (Offline). In this setup, ASF is able to ignore even the specifically-crafted message without attempting to interpret it.
Weakness: CWE-20
Which versions are affected by CVE-2021-32795?
It affects 1 product.
Products include Archisteamfarm Project Archisteamfarm.
How do I fix CVE-2021-32795?
No fix has been published for CVE-2021-32795 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2021-32795 being exploited?
There is no known exploitation of CVE-2021-32795 in the wild and no public exploit code.
Other vulnerabilities in JustArchiNET ArchiSteamFarm
Sources
Also known as GHSA-5v34-4prm-9474.