CVE-2021-36798
A Denial-of-Service (DoS) vulnerability was discovered in Team Server in HelpSystems Cobalt...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
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.
- Record
CVE-2021-36798- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Weakness
- CWE-770
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2021-36798- Updated
- 2026-11-02
EUVDEUVD-2021-23375 No score
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.
- Record
EUVD-2021-23375- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-6vhg-vrw5-pm3f No score
A Denial-of-Service (DoS) vulnerability was discovered in Team Server in HelpSystems Cobalt...
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.
- Record
GHSA-6vhg-vrw5-pm3f- Weakness
- CWE-770
- Updated
- 2026-11-02
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| PoC in GitHub | JamVayne/CobaltStrikeDos | 2021-09-06 |
| PoC in GitHub | M-Kings/CVE-2021-36798 | 2021-08-19 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, PoC in GitHub |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-36798 is a high vulnerability (CVSS 7.5) in Helpsystems Cobalt Strike, published August 9, 2021. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 4.29%, the 91st percentile. No source names a fixed version.