CVE-2021-22309Network attack vector

Sensitive-message disclosure via weak random input

Published Mar 22, 2021 · Updated Aug 3, 2024

Cryptographic weakness in Huawei USG9500-series firewalls allows remote attackers to disclose sensitive messages through brute force. An undisclosed firmware module supplies insufficiently random input to a security mechanism, making protected messages susceptible to brute-force recovery. Exploitation requires access to messages sent to and from an affected appliance; the documented consequence is confidentiality loss only.

CVSS severity4.3
Medium
EPSS probability0.77%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Cryptographic weakness in Huawei USG9500-series firewalls allows remote attackers to disclose sensitive messages through brute force. An undisclosed firmware module supplies insufficiently random input to a security mechanism, making protected messages susceptible to brute-force recovery. Exploitation requires access to messages sent to and from an affected appliance; the documented consequence is confidentiality loss only.

The record

CVE
CVE-2021-22309
Published
Mar 22, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-330, T1040
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 22, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.3HuaweiCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
5.0NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
4.0HuaweiCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N/E:F/RL:O/RC:C
7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-330Use of Insufficiently Random Values
T1040Network Sniffing

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo