CVE-2021-38296Network attack vector

RPC plaintext disclosure via recoverable encryption keys

Published Mar 10, 2022 · Updated Aug 4, 2024

Cryptographic key recovery in Apache Spark 3.1.2 and earlier allows remote attackers to decrypt captured RPC traffic offline. The bespoke mutual-authentication protocol used when spark.authenticate and spark.network.crypto.enabled are set permits recovery of the full encryption key. Exploitation requires an initial interactive attack against that optional RPC encryption mode; SASL encryption, I/O encryption, SSL, and strict transport security are unaffected.

CVSS severity7.5
High
EPSS probability1.85%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cryptographic key recovery in Apache Spark 3.1.2 and earlier allows remote attackers to decrypt captured RPC traffic offline. The bespoke mutual-authentication protocol used when spark.authenticate and spark.network.crypto.enabled are set permits recovery of the full encryption key. Exploitation requires an initial interactive attack against that optional RPC encryption mode; SASL encryption, I/O encryption, SSL, and strict transport security are unaffected.

The record

CVE
CVE-2021-38296
Published
Mar 10, 2022
Updated
Aug 4, 2024
Vendor
The Apache Software Foundation
Product
Apache Spark
Classifications
CWE-294, T1040
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 10, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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=up to and including version 3.1.2 <=3.1.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache Sparkversion=up to and including version 3.1.2 <=3.1.2

Published CVSS scores

7.5NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
5.0NIST National Vulnerability DatabaseAV:N/AC:L/Au:N/C:P/I:N/A:N

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-294Authentication Bypass by Capture-replay
T1040Network Sniffing

Public exploit references

No public exploit references are available in this record.

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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