CVE-2021-33175
EMQ X Broker versions prior to 4.2.8 are vulnerable to a denial of service attack as a result of...
EMQ X Broker versions prior to 4.2.8 are vulnerable to a denial of service attack as a result of excessive memory consumption due to the handling of untrusted inputs. These inputs cause the message broker to consume large amounts of memory, resulting in the application being terminated by the operating system.
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
EMQ X Broker versions prior to 4.2.8 are vulnerable to a denial of service attack as a result of excessive memory consumption due to the handling of untrusted inputs. These inputs cause the message broker to consume large amounts of memory, resulting in the application being terminated by the operating system.
- Record
CVE-2021-33175- 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-502, CWE-770
- Updated
- 2026-11-02
CVE List No score
EMQ X Broker versions prior to 4.2.8 are vulnerable to a denial of service attack as a result of excessive memory consumption due to the handling of untrusted inputs. These inputs cause the message broker to consume large amounts of memory, resulting in the application being terminated by the operating system.
- Record
CVE-2021-33175- Weakness
- CWE-502
- Updated
- 2026-11-02
EUVDEUVD-2021-19890 No score
EMQ X Broker versions prior to 4.2.8 are vulnerable to a denial of service attack as a result of excessive memory consumption due to the handling of untrusted inputs. These inputs cause the message broker to consume large amounts of memory, resulting in the application being terminated by the operating system.
- Record
EUVD-2021-19890- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-7vcw-x89j-vrrc No score
EMQ X Broker versions prior to 4.2.8 are vulnerable to a denial of service attack as a result of...
EMQ X Broker versions prior to 4.2.8 are vulnerable to a denial of service attack as a result of excessive memory consumption due to the handling of untrusted inputs. These inputs cause the message broker to consume large amounts of memory, resulting in the application being terminated by the operating system.
- Record
GHSA-7vcw-x89j-vrrc- Weakness
- CWE-770
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-33175 is a high vulnerability (CVSS 7.5) in Emq Technologies X Broker, published June 8, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.10%, the 65th percentile. No source names a fixed version.