JMSAppender in Log4j 1.2 is vulnerable to deserialization of untrusted dataGHSA-fp5r-v3w9-4333
HIGHFix: apache/logging-log4j2#608GHSA-fp5r-v3w9-4333 is a high-severity (CVSS 7.5) Deserialization of Untrusted Data vulnerability in log4j:log4j. 2 public exploit references exist, so weaponization risk is real. No vendor fix is recorded yet; mitigation options are listed below.
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-fp5r-v3w9-4333.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
GHSA-fp5r-v3w9-4333 by exploitation likelihood (EPSS) against impact (CVSS). In the shaded patch-first corner (EPSS 50%+, CVSS 7.0+).
Where this sits among everything scored
Of 385,987 CVEs with a current EPSS score, this one falls in the 50–90% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
log4j:log4j☕org.zenframework.z8.dependencies.commons:log4j-1.2.17Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | log4j:log4j | ≥ 1.2.0 | No fix |
| ☕Maven | org.zenframework.z8.dependencies.commons:log4j-1.2.17 | all versions | No fix |
Affected Products
log4japachefedorafedoraprojectadvanced supply chain planningoraclebusiness intelligenceoraclebusiness process management suiteoraclecommunications eagle ftp table base retrievaloracleResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for log4j:log4j, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of log4j:log4j has shipped for GHSA-fp5r-v3w9-4333 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Based on the conditions to be exploitable (see details below), the risk is much lower than Log4j 2.x and Red Hat has assessed this to be Moderate severity. This flaw has been filed for Log4j 1.x, and the corresponding flaw information for Log4j 2.x is available at:…
These are the possible mitigations for this flaw for releases version 1.x: - Comment out or remove JMSAppender in the Log4j configuration if it is used - Remove the JMSAppender class from the classpath. For example: ``` zip -q -d log4j-*.jar org/apache/log4j/net/JMSAppender.class ``` - Restrict access for the OS user on the platform running the application to prevent modifying the Log4j configuration by the attacker.Source: Red Hat security advisory for GHSA-fp5r-v3w9-4333 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| EAP 6.4.24 release | see advisory | RHSA-2022:5458 |
| EAP 6.4 log4j async | log4j | RHSA-2022:0437 |
| Red Hat Data Grid 7.3.9 | log4j | RHSA-2022:0430 |
| Red Hat Enterprise Linux 6 Extended Lifecycle Support | log4j-0:1.2.14-6.5.el6_10 | RHSA-2021:5206 |
| Red Hat Enterprise Linux 8 | parfait:0.5-8050020220124063900.6b489b78 | RHSA-2022:0290 |
| Red Hat Enterprise Linux 8.1 Update Services for SAP Solutions | parfait:0.5-8010020220124232535.d5701770 | RHSA-2022:0294 |
| Red Hat Enterprise Linux 8.2 Extended Update Support | parfait:0.5-8020020220124231008.1c5d4e8a | RHSA-2022:0291 |
| Red Hat Enterprise Linux 8.4 Extended Update Support | parfait:0.5-8040020220124230039.d304d9ed | RHSA-2022:0289 |
Frequently Asked Questions
Is GHSA-fp5r-v3w9-4333 in your dependencies?
Find it across Maven, including transitive dependencies.