CVE-2021-32795Denial of Service via Steam chat in ArchiSteamFarm
- 6.5MediumCVSS base score
- 1.7%Exploitation in 30 daysEPSS · top 22% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By GitHub_M
- 3 months later
· 3 months later
Published
- 3 years later
· 3 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium6.5 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H |
| NVDNVD · Modified | 3.1 | Medium5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 1.7% · top 22% of all CVEs (13 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.5.
Affected products
- affected >= 4.3.0.0, < 4.3.1.0
References
References3
- https://github.com/JustArchiNET/ArchiSteamFarm/security/advisories/GHSA-5v34-4prm-9474 (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://github.com/JustArchiNET/ArchiSteamFarm/commit/4cd581ec041912cf199c5512fe6d1dcaec0594c0 (opens in a new tab)x_refsource_MISCx_transferred
- https://steamcommunity.com/groups/archiasf/discussions/1/2935742047969570844/ (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-19558 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-32795)Record last updated .