GHSA-3w6p-8f82-gw8r
HIGHUsing JMSAppender in log4j configuration may lead to deserialization of untrusted data
Blast Radius
ru.yandex.clickhouse:clickhouse-jdbc-bridgeReal-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
Impact
ClickHouse JDBC Bridge uses slf4j-log4j12 1.7.32, which depends on log4j 1.2.17. It allows a remote attacker to execute code on the server, if you changed default log4j configuration by adding JMSAppender and an insecure JMS broker.
Patches
The patch version 2.0.7 removed log4j dependency by replacing slf4j-log4j12 to slf4j-jdk14. Logging configuration is also changed from log4j.properties to logging.properties.
Workarounds
- Do NOT change log4j configuration to use JMSAppender along with insecure JMS broker
- Alternatively, you can issue below command to remove
JMSAppender.class:
# install zip command if you don't have
apt-get update && apt-get install -y zip
# remove the class
zip -d clickhouse-jdbc-bridge*.jar ru/yandex/clickhouse/jdbcbridge/internal/log4j/net/JMSAppender.class
References
Please refer to CVE-2021-4104 to read more.
For more information
If you have any questions or comments about this advisory, please feel free to open an issue in the repository.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | ru.yandex.clickhouse:clickhouse-jdbc-bridge | all versions | 2.0.7 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ru.yandex.clickhouse:clickhouse-jdbc-bridge. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update ru.yandex.clickhouse:clickhouse-jdbc-bridge to 2.0.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-3w6p-8f82-gw8r is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-3w6p-8f82-gw8r is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-3w6p-8f82-gw8r. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-3w6p-8f82-gw8r in your dependencies?
O3 detects GHSA-3w6p-8f82-gw8r across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.