HelpSystems Cobalt Strike Server 4.2/4.3 Screenshot readCountedBytes Hotcobalt denial of service

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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A vulnerability classified as problematic was found in HelpSystems Cobalt Strike Server 4.2/4.3. Affected by this vulnerability is the function readCountedBytes of the component Screenshot Handler. The manipulation with an unknown input leads to a denial of service vulnerability. The CWE definition for the vulnerability is CWE-404. As an impact it is known to affect availability.

The weakness was presented 08/04/2021. The advisory is shared at This vulnerability is known as CVE-2021-36798 since 07/19/2021. The exploitation appears to be easy. Access to the local network is required for this attack. The requirement for exploitation is a single authentication. Technical details and also a public exploit are known. MITRE ATT&CK project uses the attack technique T1499 for this issue.

It is declared as proof-of-concept. It is possible to download the exploit at

Upgrading to version 4.4 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability.




CPE 2.3infoedit

CPE 2.2infoedit


VulDB Meta Base Score: 3.5
VulDB Meta Temp Score: 3.2

VulDB Base Score: 3.5
VulDB Temp Score: 3.2
VulDB Vector: 🔒
VulDB Reliability: 🔍



VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍


Class: Denial of service
CWE: CWE-404
ATT&CK: T1499

Local: No
Remote: Partially

Availability: 🔒
Access: Public
Status: Proof-of-Concept
Programming Language: 🔒
Download: 🔒
Price Prediction: 🔍
Current Price Estimation: 🔒


Threat Intelligenceinfoedit

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍


Recommended: Upgrade
Status: 🔍

Reaction Time: 🔒
0-Day Time: 🔒
Exposure Time: 🔒

Upgrade: Cobalt Strike Server 4.4


07/19/2021 CVE assigned
08/04/2021 +16 days Advisory disclosed
08/04/2021 +0 days Countermeasure disclosed
08/04/2021 +0 days VulDB entry created
08/08/2021 +4 days VulDB last update


Status: Confirmed

CVE: CVE-2021-36798 (🔒)
scip Labs:


Created: 08/04/2021 08:02 PM
Updated: 08/08/2021 07:51 AM
Changes: (1) source_cve_assigned
Complete: 🔍
Submitter: misc


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