CVE-2017-5929 is a critical-severity (CVSS 9.8) Deserialization of Untrusted Data vulnerability in ch.qos.logback:logback-classic. A fix is available for ch.qos.logback:logback-classic — see the affected versions and patch details below.
QOS.ch Logback vulnerable to Deserialization of Untrusted Data
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
ch.qos.logback:logback-classic☕ch.qos.logback:logback-coreReal-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
QOS.ch Logback before 1.2.0 has a serialization vulnerability affecting the SocketServer and ServerSocketReceiver components. The RemoteStreamAppenderClient class in logback-classic and the SocketNode classes in logback-classic and logback-access allow data to be deserialized over a Java Socket, via an ObjectInputStream, without validating the data beforehand. When data is received from the Socket, to be logged, it is deserialized into Java objects.An attacker can exploit this vulnerability by sending malicious, serialized Java objects over the connection to the Socket, which may result in execution of arbitrary code when those objects are deserialized. Note that although logback-core is implicated by the Logback project here, the Sonatype Security Research team discovered that the vulnerability is actually present in the logback-classic and logback-access components. Versions prior to 1.2.0 are vulnerable, as stated in the advisory.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | ch.qos.logback:logback-classic | all versions | 1.2.0ch.qos.logback:logback-classic:1.2.0 |
| ☕Maven | ch.qos.logback:logback-core | all versions | 1.2.0ch.qos.logback:logback-core:1.2.0 |
Affected Products
logbackqossatelliteredhatsatellite capsuleredhatDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ch.qos.logback:logback-classic, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update ch.qos.logback:logback-classic to 1.2.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2017-5929 is resolved across your whole dependency graph.
Workarounds
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.
The vulnerability applies to logback-classic and logback-core.There is no documented evidence in the official upstream advisory that logback-json-core is affected.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Fuse 7.6.0 | logback-core | RHSA-2020:0983 |
| Red Hat JBoss A-MQ 6.3 | camel | RHSA-2017:1832 |
| Red Hat JBoss BPMS 6.4 | logback-core | RHSA-2017:1675 |
| Red Hat JBoss BRMS 6.4 | logback-core | RHSA-2017:1676 |
| Red Hat Satellite 6.4 for RHEL 7 | ansiblerole-insights-client-0:1.5-1.el7sat | RHSA-2018:2927 |
Frequently Asked Questions
Is CVE-2017-5929 in your dependencies?
Find it across Maven, including transitive dependencies.