High severity · published Aug 9, 2021
CVE-2021-36798
A Denial-of-Service (DoS) vulnerability was discovered in Team Server in HelpSystems Cobalt Strike 4.2 and 4.3
7.5
CVSS
4.3%
EPSS
No
On KEV
Description
A Denial-of-Service (DoS) vulnerability was discovered in Team Server in HelpSystems Cobalt Strike 4.2 and 4.3. It allows remote attackers to crash the C2 server thread and block beacons' communication with it.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)4.3% · higher than 91% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CS
Cobalt Strike · Helpsystems
4.2; 4.3 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-36798
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-36798
Exploit
https://labs.sentinelone.com/hotcobalt-new-cobalt-strike-dos-vulnerability-that-lets-you-halt-operations/
Release Notes
https://www.cobaltstrike.com/releasenotes.txt
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