CVE-2023-34455
HIGHsnappy-java's unchecked chunk length leads to DoS
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
org.xerial.snappy:snappy-javaReal-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
snappy-java is a fast compressor/decompressor for Java. Due to use of an unchecked chunk length, an unrecoverable fatal error can occur in versions prior to 1.1.10.1.
The code in the function hasNextChunk in the fileSnappyInputStream.java checks if a given stream has more chunks to read. It does that by attempting to read 4 bytes. If it wasn’t possible to read the 4 bytes, the function returns false. Otherwise, if 4 bytes were available, the code treats them as the length of the next chunk.
In the case that the compressed variable is null, a byte array is allocated with the size given by the input data. Since the code doesn’t test the legality of the chunkSize variable, it is possible to pass a negative number (such as 0xFFFFFFFF which is -1), which will cause the code to raise a java.lang.NegativeArraySizeException exception. A worse case would happen when passing a huge positive value (such as 0x7FFFFFFF), which would raise the fatal java.lang.OutOfMemoryError error.
Version 1.1.10.1 contains a patch for this issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.xerial.snappy:snappy-java | all versions | 1.1.10.1 |
Research 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 org.xerial.snappy:snappy-java. 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 org.xerial.snappy:snappy-java to 1.1.10.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-34455 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 CVE-2023-34455 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 CVE-2023-34455. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-34455 in your dependencies?
O3 detects CVE-2023-34455 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.