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CVE-2021-32795

Denial of Service via Steam chat in ArchiSteamFarm

6.5 Medium

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.

Attack profile

How easy it is to exploit

Attack vector
Network
Complexity
High
Privileges needed
None
User interaction
None

What an attacker can affect

Confidentiality
Low
Integrity
None
Availability
High

Exploit likelihood

1.72%Down 0.1 points since Jul 27, 2021
90%50%10%1%

What each source reports

CVE List Score used 6.5

Denial of Service via Steam chat in ArchiSteamFarm

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.

Record
CVE-2021-32795
CVSS 3.1
6.5 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H
Weakness
CWE-20
Updated
2026-11-02
EUVDEUVD-2021-19558 6.5

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.

Record
EUVD-2021-19558
CVSS 3.1
6.5 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H
Updated
2026-11-03
NVD 6.5

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.

Record
CVE-2021-32795
CVSS 3.1
6.5 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H
CVSS 3.1
5.9 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0
4.3 MediumAV:N/AC:M/Au:N/C:N/I:N/A:P
Weakness
CWE-20
Updated
2026-11-02
OSV 5.9

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.

Record
CVE-2021-32795
CVSS 3.1
5.9 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated
2026-11-02

Affected products

History

History
RecordedChangedSources
aliasesEUVD
first indexedCVE List, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-32795 is a medium vulnerability (CVSS 6.5) in Archisteamfarm Project Archisteamfarm, published July 26, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.72%, the 77th percentile. No source names a fixed version.

References

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