CVE-2021-36798 json
A Denial-of-Service (DoS) vulnerability was discovered in Team Server in HelpSystems Cobalt Strike 4.2 and 4.3.
published 2021-08-09 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-23375
- cvss
- 7.5
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 4.3%
- EPSS 4.3% chance of exploitation in 30 days, percentile 91%
- public exploits
- 0
- none known
Summary
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.
Exploit prediction
4.29% chance of exploitation in the next 30 days, higher than 91% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- labs.sentinelone.com https://labs.sentinelone.com/hotcobalt-new-cobalt-strike-dos-vulnerability-that-lets-you-halt-operations/ referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVD | 2.0 | 5.0 | AV:N/AC:L/Au:N/C:N/I:N/A:P |
Classification
- Weakness
-
- CWE-770 Allocation of Resources Without Limits or Throttling
References
-
labs.sentinelone.com
/hotcobalt-new-cobalt-strike-dos-vulnerability-that-lets-you-halt-operations/
exploit, third-party-advisory
-
cobaltstrike.com
/releasenotes.txt
release-notes, vendor-advisory
Sources
- CVE List CVE-2021-36798
- NVD CVE-2021-36798
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