Deserialization of Untrusted Data in Neo4j

published 2021-08-05 5 y ago modified 2026-09-08 2 mo ago also BIT-neo4j-2021-34371 , BIT-neo4j-enterprise-2021-34371 , EUVD-2021-2097 , GHSA-pc4w-8v5j-29w9

cvss: 9.8; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 13.4%; EPSS 13.4% chance of exploitation in 30 days, percentile 96%
public exploits: 0; none known

Neo4j through 3.4.18 (with the shell server enabled) exposes an RMI service that arbitrarily deserializes Java objects, e.g., through setSessionVariable. An attacker can abuse this for remote code execution because there are dependencies with exploitable gadget chains.

Patch / fix

fixed in 2

maven org.neo4j:neo4j 3.5.0
bitnami neo4j 3.4.19

Exploit prediction

13.39% chance of exploitation in the next 30 days, higher than 96% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

exploit-db.com https://www.exploit-db.com/exploits/50170 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
GitHub	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P
OSV	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem	package	affected	fixed in
maven	org.neo4j:neo4j	<3.5.0	3.5.0
bitnami	neo4j	<3.4.19	3.4.19
bitnami	neo4j-enterprise	<=3.4.18	no fix listed

Classification

Weakness

CWE-502 Deserialization of Untrusted Data

References

exploit-db.com /exploits/50170
web, exploit, third-party-advisory, vdb-entry, advisory
nvd.nist.gov /vuln/detail/CVE-2021-34371
advisory, web
github.com /neo4j/neo4j
package

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary