# What is CVE-2021-4104?

> CVE-2021-4104 is a high-severity flaw (CVSS 7.5) in Log4j from Apache, published on 14 December 2021. It is not on the list of flaws known to be exploited today. The latest forecast puts its chance of use in the next 30 days at 81%. If you run an affected version, plan in the vendor’s fix.

Canonical page: https://www.precursorintelligence.com/what-is/cve-2021-4104

## At a glance

- **Verdict:** Fix this soon. Not confirmed as exploited yet, but serious or likely enough that it should not wait for a quiet month.
- **Precursor Intelligence risk score:** 66 out of 100 (Medium); action: Plan remediation. Kept up to date as the evidence changes.
- **Severity:** High (CVSS 7.5 out of 10)
- **Known to be exploited:** No, not on the list of flaws known to be exploited today
- **Chance of use in the next 30 days:** 81% (latest exploit-likelihood forecast)
- **Published:** 14 December 2021
- **Record last updated:** 22 December 2023
- **Main product:** Log4j from Apache
- **Affected products:** 46

## What is CVE-2021-4104? In plain terms

It can be attacked from anywhere on the internet with an ordinary user account, and nobody has to click anything. If it works, the attacker can read data, change data and take it offline.

### The official description

JMSAppender in Log4j 1.2 is vulnerable to deserialization of untrusted data when the attacker has write access to the Log4j configuration. The attacker can provide TopicBindingName and TopicConnectionFactoryBindingName configurations causing JMSAppender to perform JNDI requests that result in remote code execution in a similar fashion to CVE-2021-44228. Note this issue only affects Log4j 1.2 when specifically configured to use JMSAppender, which is not the default. Apache Log4j 1.2 reached end of life in August 2015. Users should upgrade to Log4j 2 as it addresses numerous other issues from the previous versions.

### What kind of flaw is it?

- CWE-502: Deserialization of Untrusted Data

### How an attack on it works

- Where an attacker can be: Anywhere on the internet
- How hard it is to pull off: Hard: conditions must line up
- Login needed first: An ordinary user account
- Does someone have to click: No, nobody has to do anything
- What an attacker gets: Can read data, change data and take it offline

Severity vector: `CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H`

## Is CVE-2021-4104 being exploited? Not that we know of

It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 81%. That can change at any time, which is why we keep watching.

Exploit likelihood over the last 7 days: 81%, 81%, 81%, 81%, 81%, 81%, 81%.

### Timeline

- 14 December 2021: Published
- 22 December 2023: Record last updated
- 19 November 2025: Exploit likelihood jumped
- 22 November 2025: Exploit likelihood fell

### How Precursor Intelligence ranks it

CVE-2021-4104 scores **66 out of 100 (Medium)**, with the action "Plan remediation".

Every published flaw gets a risk score from 0 to 100, kept up to date as the evidence changes. Four things go into the score, from the one that counts most to the ones that count less:

- Evidence it is being exploited: biggest factor
- How severe it is: strong factor
- How widely exposed it is: smaller factor
- Threat activity around it: smaller factor

85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score. When this flaw matches software you track, it lands in your list with its score and the reasons behind it.

## Who is affected by CVE-2021-4104?

The published record lists 46 products. Versions are as published: "before 12.0.0.4.0" means every version up to, but not including, 12.0.0.4.0.

- [Log4j](https://www.precursorintelligence.com/product/apache/log4j) by [Apache](https://www.precursorintelligence.com/vendors/apache) (Application): 1.2
- [Communications Unified Inventory Management](https://www.precursorintelligence.com/product/oracle/communications_unified_inventory_management) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 7.3.4, 7.3.5, 7.4.1, 7.4.2
- [Retail Allocation](https://www.precursorintelligence.com/product/oracle/retail_allocation) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 14.1.3.2, 15.0.3.1, 16.0.3, 19.0.1
- [Business Intelligence](https://www.precursorintelligence.com/product/oracle/business_intelligence) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 5.9.0.0.0, 12.2.1.3.0, 12.2.1.4.0
- [Enterprise Linux](https://www.precursorintelligence.com/product/redhat/enterprise_linux) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Operating system): 6.0, 7.0, 8.0
- [Financial Services Revenue Management and Billing Analytics](https://www.precursorintelligence.com/product/oracle/financial_services_revenue_management_and_billing_analytics) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 2.7.0.0, 2.7.0.1, 2.8.0.0
- [Openshift Container Platform](https://www.precursorintelligence.com/product/redhat/openshift_container_platform) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Application): 4.6, 4.7, 4.8
- [Utilities Testing Accelerator](https://www.precursorintelligence.com/product/oracle/utilities_testing_accelerator) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 6.0.0.1.1, 6.0.0.2.2, 6.0.0.3.1
- [Weblogic Server](https://www.precursorintelligence.com/product/oracle/weblogic_server) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 12.2.1.3.0, 12.2.1.4.0, 14.1.1.0.0
- [Advanced Supply Chain Planning](https://www.precursorintelligence.com/product/oracle/advanced_supply_chain_planning) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 12.1, 12.2
- [Business Process Management Suite](https://www.precursorintelligence.com/product/oracle/business_process_management_suite) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 12.2.1.3.0, 12.2.1.4.0
- [Communications Offline Mediation Controller](https://www.precursorintelligence.com/product/oracle/communications_offline_mediation_controller) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): before 12.0.0.4.0, 12.0.0.5.0
- [Enterprise Manager Base Platform](https://www.precursorintelligence.com/product/oracle/enterprise_manager_base_platform) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 13.4.0.0, 13.5.0.0
- [Identity Management Suite](https://www.precursorintelligence.com/product/oracle/identity_management_suite) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 12.2.1.3.0, 12.2.1.4.0
- [Jboss a-Mq](https://www.precursorintelligence.com/product/redhat/jboss_a-mq) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Application): 6.0.0, 7
- [Jboss Enterprise Application Platform](https://www.precursorintelligence.com/product/redhat/jboss_enterprise_application_platform) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Application): 6.0.0, 7.0
- [Jboss Fuse](https://www.precursorintelligence.com/product/redhat/jboss_fuse) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Application): 6.0.0, 7.0.0
- [Codeready Studio](https://www.precursorintelligence.com/product/redhat/codeready_studio) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Application): 12.0
- [Communications Eagle FTP Table Base Retrieval](https://www.precursorintelligence.com/product/oracle/communications_eagle_ftp_table_base_retrieval) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 4.5
- [Communications Messaging Server](https://www.precursorintelligence.com/product/oracle/communications_messaging_server) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 8.1
- [Communications Network Integrity](https://www.precursorintelligence.com/product/oracle/communications_network_integrity) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 7.3.6
- [E-Business Suite Cloud Manager and Cloud Backup Module](https://www.precursorintelligence.com/product/oracle/e-business_suite_cloud_manager_and_cloud_backup_module) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 2.2.1.1.1
- [Fedora](https://www.precursorintelligence.com/product/fedoraproject/fedora) by [Fedoraproject](https://www.precursorintelligence.com/vendors/fedoraproject) (Operating system): 35
- [Fusion Middleware Common Libraries and Tools](https://www.precursorintelligence.com/product/oracle/fusion_middleware_common_libraries_and_tools) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 12.2.1.4.0
- [Goldengate](https://www.precursorintelligence.com/product/oracle/goldengate) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): version not specified
- [Healthcare Data Repository](https://www.precursorintelligence.com/product/oracle/healthcare_data_repository) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 8.1.0
- [Hyperion Data Relationship Management](https://www.precursorintelligence.com/product/oracle/hyperion_data_relationship_management) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): before 11.2.8.0
- [Hyperion Infrastructure Technology](https://www.precursorintelligence.com/product/oracle/hyperion_infrastructure_technology) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): before 11.2.8.0
- [Integration Camel K](https://www.precursorintelligence.com/product/redhat/integration_camel_k) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Application): version not specified
- [Integration Camel Quarkus](https://www.precursorintelligence.com/product/redhat/integration_camel_quarkus) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Application): version not specified
- [Jboss a-Mq Streaming](https://www.precursorintelligence.com/product/redhat/jboss_a-mq_streaming) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Application): version not specified
- [Jboss Data Grid](https://www.precursorintelligence.com/product/redhat/jboss_data_grid) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Application): 7.0.0
- [Jboss Data Virtualization](https://www.precursorintelligence.com/product/redhat/jboss_data_virtualization) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Application): 6.0.0
- [Jboss Fuse Service Works](https://www.precursorintelligence.com/product/redhat/jboss_fuse_service_works) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Application): 6.0
- [Jboss Operations Network](https://www.precursorintelligence.com/product/redhat/jboss_operations_network) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Application): 3.0
- [Jboss Web Server](https://www.precursorintelligence.com/product/redhat/jboss_web_server) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Application): 3.0
- [Jdeveloper](https://www.precursorintelligence.com/product/oracle/jdeveloper) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 12.2.1.3.0
- [Mysql Enterprise Monitor](https://www.precursorintelligence.com/product/oracle/mysql_enterprise_monitor) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): up to 8.0.29
- [Openshift Application Runtimes](https://www.precursorintelligence.com/product/redhat/openshift_application_runtimes) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Application): version not specified
- [Process Automation](https://www.precursorintelligence.com/product/redhat/process_automation) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Application): 7.0
- [Retail Extract Transform and Load](https://www.precursorintelligence.com/product/oracle/retail_extract_transform_and_load) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 13.2.5
- [Single Sign-on](https://www.precursorintelligence.com/product/redhat/single_sign-on) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Application): 7.0
- [Software Collections](https://www.precursorintelligence.com/product/redhat/software_collections) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Application): version not specified
- [Stream Analytics](https://www.precursorintelligence.com/product/oracle/stream_analytics) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): version not specified
- [Timesten Grid](https://www.precursorintelligence.com/product/oracle/timesten_grid) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): version not specified
- [Tuxedo](https://www.precursorintelligence.com/product/oracle/tuxedo) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 12.2.2.0.0

## How do I fix CVE-2021-4104?

1. **Check whether you run it.** Compare your versions with the affected products above. Not sure what you run? Precursor Intelligence can work it out from your public website, or you can pick it from a list.
2. **Apply the vendor’s fix.** Install the latest update from the vendor. The references list where the vendor has published details.
3. **If you can’t patch today.** Follow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in.
4. **Keep an eye on it.** Track the product and we tell you as soon as we spot this flaw on the list of exploited flaws, or a jump in its exploit likelihood.

### References

- [openwall.com](http://www.openwall.com/lists/oss-security/2022/01/18/3)
- [access.redhat.com](https://access.redhat.com/security/cve/CVE-2021-4104)
- [github.com](https://github.com/apache/logging-log4j2/pull/608#issuecomment-990494126)
- [psirt.global.sonicwall.com](https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0033)
- [security.gentoo.org](https://security.gentoo.org/glsa/202209-02)
- [security.gentoo.org](https://security.gentoo.org/glsa/202310-16)
- [security.gentoo.org](https://security.gentoo.org/glsa/202312-02)
- [security.gentoo.org](https://security.gentoo.org/glsa/202312-04)
- [security.netapp.com](https://security.netapp.com/advisory/ntap-20211223-0007/)
- [cve.org](https://www.cve.org/CVERecord?id=CVE-2021-44228)
- [kb.cert.org](https://www.kb.cert.org/vuls/id/930724)
- [oracle.com](https://www.oracle.com/security-alerts/cpuapr2022.html)
- [oracle.com](https://www.oracle.com/security-alerts/cpujan2022.html)
- [oracle.com](https://www.oracle.com/security-alerts/cpujul2022.html)

## Questions

### What is CVE-2021-4104?

CVE-2021-4104 is a high-severity flaw in Log4j from Apache, published on 14 December 2021. It can be attacked from anywhere on the internet with an ordinary user account, and nobody has to click anything. If it works, the attacker can read data, change data and take it offline.

### How serious is CVE-2021-4104?

It scores 7.5 out of 10 on the CVSS severity scale, which is high. Our risk score for CVE-2021-4104 is 66 out of 100, which is Medium. Its action is "Plan remediation". Not confirmed as exploited yet, but serious or likely enough that it should not wait for a quiet month.

### Is CVE-2021-4104 being exploited?

It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 81%. That can change at any time, which is why we keep watching.

### Which versions does CVE-2021-4104 affect?

For Log4j from Apache: 1.2. The record lists 46 products in all, each with its versions, under "Who is affected" on this page.

### How do I fix CVE-2021-4104?

Install the update the vendor names in its advisory. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet.

## Does CVE-2021-4104 affect you?

Precursor Intelligence keeps checking for you:

- **Tell us what you run.** Pick your software from a list, or let us work it out from your website.
- **We match it to every flaw.** Over 400,000 published flaws, checked against your list.
- **Ranked by real-world risk.** Every flaw gets a 0 to 100 risk score, kept up to date, led by evidence criminals are using it.
- **Told as soon as we know.** An alert by email, in the app or by webhook to your own tools.

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