CVE-2023-42809Public exploitNetwork attack vector

Remote code execution via unvalidated server objects

Published Oct 4, 2023 · Updated Sep 19, 2024

Unsafe deserialization in Redisson before 3.22.0 allows remote attackers to execute arbitrary code through malicious Redis responses. When SerializationCodec handles an object response, CommandDecoder passes attacker-controlled bytes to ObjectInputStream.readObject without a class allowlist. Exploitation requires the affected codec, communication with a malicious Redis server, and a usable gadget chain on the application classpath, enabling compromise of the client host.

CVSS severity9.4
Critical
EPSS probability1.04%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unsafe deserialization in Redisson before 3.22.0 allows remote attackers to execute arbitrary code through malicious Redis responses. When SerializationCodec handles an object response, CommandDecoder passes attacker-controlled bytes to ObjectInputStream.readObject without a class allowlist. Exploitation requires the affected codec, communication with a malicious Redis server, and a usable gadget chain on the application classpath, enabling compromise of the client host.

The record

CVE
CVE-2023-42809
Published
Oct 4, 2023
Updated
Sep 19, 2024
Vendor
Redisson
Product
Redisson
Classifications
CWE-502, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 4, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 19, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 3.22.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Redisson · Redissonversion=< 3.22.0

Published CVSS scores

9.4GitHub Advisory DatabaseCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
8.8National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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