CVE-2018-12541

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2018-10-10 · updated 2026-06-17
Weakness: CWE-789

Description

In version from 3.0.0 to 3.5.3 of Eclipse Vert.x, the WebSocket HTTP upgrade implementation buffers the full http request before doing the handshake, holding the entire request body in memory. There should be a reasonnable limit (8192 bytes) above which the WebSocket gets an HTTP response with the 413 status code and the connection gets closed.

Affected products

Eclipse Foundation Eclipse Vert.x: from 3.0.0 before 3.5.4 — fixed in 3.5.4

How to fix

Upgrade to a fixed version: Eclipse Foundation Eclipse Vert.x 3.5.4. Check the vendor advisory for mitigations.

References

https://access.redhat.com/errata/RHSA-2018:2946
https://bugs.eclipse.org/bugs/show_bug.cgi?id=539170
https://github.com/eclipse-vertx/vert.x/issues/2648
https://lists.apache.org/thread.html/r01123837ffbfdf5809e0a4ac354ad546e4ca8f18df89ee5a10eeb81b%40%3Cissues.bookkeeper.apache.org%3E
https://lists.apache.org/thread.html/r11789cd6d67ecca2d6f6bbb11e34495e68ee99287b6c59edf5b1a09c%40%3Ccommits.pulsar.apache.org%3E
https://lists.apache.org/thread.html/r1af71105539fe01fcecb92d2ecd8eea56c515fb1c80ecab4df424553%40%3Cissues.bookkeeper.apache.org%3E
https://lists.apache.org/thread.html/r344235b1aea2f7fa2381495df1d77d02b595e3d7e4626e701f7c1062%40%3Ccommits.pulsar.apache.org%3E
https://lists.apache.org/thread.html/r362835e6c7f34324ed24e318b363fcdd20cea91d0cea0b2e1164f73e%40%3Cissues.bookkeeper.apache.org%3E
https://lists.apache.org/thread.html/r3da899890536af744dec897fbc561fd9810ac45e79a16164b53c31b2%40%3Ccommits.pulsar.apache.org%3E
https://lists.apache.org/thread.html/r79789a0afb184abd13a2c07016e6e7ab8e64331f332b630bf82a2eed%40%3Ccommits.pulsar.apache.org%3E
https://lists.apache.org/thread.html/r8db0431ecf93f2dd2128db5ddca897b33ba883b7f126648d6a9e4c47%40%3Ccommits.pulsar.apache.org%3E
https://lists.apache.org/thread.html/r98dc06e2b1c498d0e9eb5038d8e1aefd24e411e50522e7082dd9e0b7%40%3Ccommits.bookkeeper.apache.org%3E

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