CVE-2021-33527
OS Command Injection in mbDIALUP <= 3.9R0.0
In MB connect line mbDIALUP versions <= 3.9R0.0 a remote attacker can send a specifically crafted HTTP request to the service running with NT AUTHORITY\SYSTEM that will not correctly validate the input. This can lead to an arbitrary code execution with the privileges of the service.
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
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
OS Command Injection in mbDIALUP <= 3.9R0.0
In MB connect line mbDIALUP versions <= 3.9R0.0 a remote attacker can send a specifically crafted HTTP request to the service running with NT AUTHORITY\SYSTEM that will not correctly validate the input. This can lead to an arbitrary code execution with the privileges of the service.
- Record
CVE-2021-33527- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-20
- Updated
- 2026-11-02
EUVDEUVD-2021-20219
In MB connect line mbDIALUP versions <= 3.9R0.0 a remote attacker can send a specifically crafted HTTP request to the service running with NT AUTHORITY\SYSTEM that will not correctly validate the input. This can lead to an arbitrary code execution with the privileges of the service.
- Record
EUVD-2021-20219- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-hrmp-939q-g4mq
In MB connect line mbDIALUP versions <= 3.9R0.0 a low privileged local attacker can send a...
In MB connect line mbDIALUP versions <= 3.9R0.0 a low privileged local attacker can send a command to the service running with NT AUTHORITY\SYSTEM that won't be validated correctly and allows for an arbitrary code execution with the privileges of the service.
- Record
GHSA-hrmp-939q-g4mq- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-20, CWE-269
- Updated
- 2026-11-02
NVD
In MB connect line mbDIALUP versions <= 3.9R0.0 a remote attacker can send a specifically crafted HTTP request to the service running with NT AUTHORITY\SYSTEM that will not correctly validate the input. This can lead to an arbitrary code execution with the privileges of the service.
- Record
CVE-2021-33527- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 10.0 High
AV:N/AC:L/Au:N/C:C/I:C/A:C - Weakness
- CWE-20
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-33527 is a critical vulnerability (CVSS 9.8) in Mb Connect Line Mbdialup, published August 2, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 4.52%, the 91st percentile. No source names a fixed version.