How should we interpret CVSS severity scores?

CVSS estimates technical severity, but it does not automatically equal business risk. Prioritize using context like internet exposure, asset criticality, known exploitation, and whether compensating controls exist. A Medium CVSS on an exposed production system can be more urgent than a Critical on an isolated non-production host.

Vulnerability Database

Q: What is a Vulnerability (CVE) and why does it matter?

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

Q: What's the difference between a vulnerability, an exploit, and a zero-day?

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. Risk increases sharply when exploitation becomes reliable or widespread.

Q: Why do vulnerabilities keep reappearing in our environment?

Recurring findings usually come from incomplete asset discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host.

Q: How do we prioritize remediation without burning out the team?

Use a repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress so remediation is steady, not reactive.

Q: How can SynScan help reduce vulnerability risk over time?

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.

328,409

Total vulnerabilities in the database

Security Advisory for "Log4Shell"

Impact

A highly critical 0-day exploit (CVE-2021-44228) is found in Apache log4j 2 library on December 9, 2021.

This affects Apache log4j versions from 2.0-beta9 to 2.14.1 (inclusive).

This vulnerability allows a remote attacker to execute code on the server if the system logs an attacker-controlled string value with the attacker's JNDI LDAP server lookup.

Another vulnerability related to the same library, which was discovered on 12/14/2021 (CVE-2021-45046) and revealed another Remote Code Execution vulnerability, has been investigated by Hazelcast team as well and it is found that it does not affect Hazelcast Products under default configurations.

The finding of CVE-2021-45105 on 12/14/2021, which can cause a Denial of Service attack, was investigated by Hazelcast team and it is confirmed that it does not affect Hazelcast Products under default configurations.

The finding of CVE-2021-44832 on 12/28/2021, which is a medium vulnerability, is investigated by our security team as well, and not considered to be as critical. It requires attacker to be able to modify logging configuration, which means attacker can modify the filesystem and/or can already execute arbitrary code which is more of a general security breach rather than something log4j specific.

Note that Hazelcast IMDG and IMDG Enterprise itself is not affected.

However, given version distributions are considered to be vulnerable since related ZIP and TGZ distributions contain a vulnerable Hazelcast Management Center version.

Patches

CVE-2021-44228 is fixed in log4j 2.15.0. CVE-2021-45046 is fixed in log4j 2.16.0. CVE-2021-45105 is fixed in log4j 2.17.0. CVE-2021-44832 is fixed in log4j 2.17.1.

As of 12/21/2021, Hazelcast team has released a new version of all affected products that upgrades log4j to 2.17.0 as listed below: Hazelcast Management Center 4.2021.12-1, Hazelcast Management Center 5.0.4. Hazelcast IMDG and IMDG Enterprise 4.0.5, 4.1.8 and 4.2.4. Hazelcast Jet 4.5.3. Hazelcast Platform 5.0.2.

As of 01/06/2022, Hazelcast Management Center 4.2022.01 with the updated log4j 2.17.1 is released. log4j2.17.1 will be included in Management Center 5.1 that is expected to be released in February.

Hazelcast recommends upgrading to the latest versions available.

Workarounds

For users that an upgrade is not an option, below mitigations can be applied.

Disabling lookups via Environment Variable

Setting the environment variable LOG4J_FORMAT_MSG_NO_LOOKUPS=true . This option is the easiest to apply for containerized environments.

Disabling lookups in log4j2 configuration

Another good option since there is no need to replace JARs or no need to modify logging configuration file, users who cannot upgrade to 2.17.0 can mitigate the exposure by:

Users of Log4j 2.10 or greater may add -Dlog4j2.formatMsgNoLookups=true as a command line option or add -Dlog4j2.formatMsgNoLookups=true in a log4j2.component.properties file on the classpath to prevent lookups in log event messages. Users since Log4j 2.7 may specify %m{nolookups} in the PatternLayout configuration to prevent lookups in log event messages. As an example; users deploying Hazelcast Management Center via helm charts can do the following to disable lookups and restart in one command:

helm upgrade <release-name> hazelcast/hazelcast --set mancenter.javaOpts="<javaOpts> -Dlog4j2.formatMsgNoLookups=true"

Where <release-name> is the release name and <javaOpts> is existing java options user has added previously.

Removing the JndiLookup from classpath

Remove the JndiLookup and JndiManager classes from the log4j-core jar. Note that removal of the JndiManager will cause the JndiContextSelector and JMSAppender to no longer function.

References

https://nvd.nist.gov/vuln/detail/CVE-2021-44228 https://nvd.nist.gov/vuln/detail/CVE-2021-45046 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-45105 https://nvd.nist.gov/vuln/detail/CVE-2021-44832 https://logging.apache.org/log4j/2.x/index.html

For more information

If you have any questions or comments about this advisory:

Open an issue in our repo
Slack us at Hazelcast Community Slack

Published: Jan 21, 2022
Updated: Apr 14, 2023
GHSA: GHSA-v57x-gxfj-484q
Severity: Critical
Exploit:

CVSS v3:

Severity: Unknown
Score:
AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

CWEs:

OWASP TOP 10:

A8 - Insecure Deserialization

Affected Software
References

Software	From	Fixed in
com.hazelcast.jet / hazelcast-jet	4.1	4.5.3
com.hazelcast / hazelcast	5.0	5.0.2
com.hazelcast / hazelcast	4.0.0	4.0.5
com.hazelcast / hazelcast	4.1.1	4.1.8
com.hazelcast / hazelcast	4.2	4.2.4

https://github.com/hazelcast/hazelcast/security/advisories/GHSA-v57x-gxfj-484q

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Frequently Asked Questions

What is a Vulnerability (CVE) and why does it matter?

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.