CVE-2021-38296 | Apache Spark Key Negotiation Vulnerability

Apache Spark supports end-to-end encryption of RPC connections via "spark.authenticate" and "spark.network.crypto.enabled". In versions 3.1.2 and earlier, it uses a bespoke mutual authentication protocol that allows for full encryption key recovery. After an initial interactive attack, this would allow someone to decrypt plaintext traffic offline. Note that this does not affect security mechanisms controlled by "spark.authenticate.enableSaslEncryption", "spark.io.encryption.enabled", "spark.ssl", "spark.ui.strictTransportSecurity". Update to Apache Spark 3.1.3 or later

Published: 2022-03-10 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-38296 is rated Moderate Risk (59.8/100): CVSS High severity, with medium exploitation likelihood (EPSS 2.15%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-38296

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-30 1.93% 2.15% +0.21%
2 2026-05-27 2.15% 1.93% -0.21%
3 2026-05-13 2.15%

Full EPSS history (17 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-38296

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
10.0 2.9 [email protected]

Weakness enumeration for CVE-2021-38296

GitHub Security Advisory for CVE-2021-38296

GHSA-9rr6-jpg7-9jg6 · Severity: high · Ecosystem: maven — Authentication Bypass by Capture-replay in Apache Spark

Affected software / configurations for CVE-2021-38296

Vendor Product Version Raw CPE
apache spark < 3.1.3 cpe:2.3:a:apache:spark:*:*:*:*:*:*:*:*
oracle financial_services_crime_and_compliance_management_studio 8.0.8.2.0 cpe:2.3:a:oracle:financial_services_crime_and_compliance_management_studio:8.0.8.2.0:*:*:*:*:*:*:*
oracle financial_services_crime_and_compliance_management_studio 8.0.8.3.0 cpe:2.3:a:oracle:financial_services_crime_and_compliance_management_studio:8.0.8.3.0:*:*:*:*:*:*:*

References for CVE-2021-38296

cvelogic Threat Intelligence