CVE-2017-20189
CWE-502Published: January 22, 2024· Updated: Jun 17, 2026
Official Description
In Clojure before 1.9.0, classes can be used to construct a serialized object that executes arbitrary code upon deserialization. This is relevant if a server deserializes untrusted objects.
Risk Analysis
Clojure is vulnerable to arbitrary code execution when deserializing untrusted objects, which can be leveraged by attackers to compromise a server. This is a critical risk for any application that handles serialized data from untrusted sources.
There is no public exploit known for this issue, and it is not in the KEV catalog. It is remotely exploitable with low attack complexity.
Upgrade to Clojure version 1.9.0 or later and avoid deserializing untrusted objects.
Technical Analysis
CVE-2017-20189 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.
From a weakness classification perspective (CWE-502): Insecure deserialization vulnerabilities allow attackers to inject malicious objects during deserialization, potentially enabling remote code execution.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (11)
Quick Facts
Related CVEs (CWE-502)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2017-20189 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts