CVE-2024-27317: In Pulsar Functions Worker, authenticated users can upload functions in jar or nar files.

In Pulsar Functions Worker, authenticated users can upload functions in jar or nar files.

In Pulsar Functions Worker, authenticated users can upload functions in jar or nar files. These files, essentially zip files, are extracted by the Functions Worker. However, if a malicious file is uploaded, it could exploit a directory traversal vulnerability. This occurs when the filenames in the zip files, which aren't properly validated, contain special elements like "..", altering the directory path. This could allow an attacker to create or modify files outside of the designated extraction directory, potentially influencing system behavior. This vulnerability also applies to the Pulsar Broker when it is configured with "functionsWorkerEnabled=true". This issue affects Apache Pulsar versions from 2.4.0 to 2.10.5, from 2.11.0 to 2.11.3, from 3.0.0 to 3.0.2, from 3.1.0 to 3.1.2, and 3.2.0. 2.10 Pulsar Function Worker users should upgrade to at least 2.10.6. 2.11 Pulsar Function Worker users should upgrade to at least 2.11.4. 3.0 Pulsar Function Worker users should upgrade to at least 3.0.3. 3.1 Pulsar Function Worker users should upgrade to at least 3.1.3. 3.2 Pulsar Function Worker users should upgrade to at least 3.2.1. Users operating versions prior to those listed above s

Description from the National Vulnerability Database, published by security@apache.org

What it means for a small business

Apache Pulsar runs on web servers, so this is mostly your hosting company's to fix. On shared hosting you can't patch it yourself, but you can ask.

Ask your host whether your server runs it, whether it's updated, and on what date. A good host answers that in a day.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 57%, top 1% of all CVEs. That’s high: fix it ahead of everything else on the list. Scored October 29, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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