Riskcovery

CVE-2025-55039

Apache Spark, Apache Spark: RPC encryption defaults to unauthenticated AES-CTR mode, enabling man-in-the-middle ciphertext modification attacks

State
Published
Severity
6.5 Medium
Published
Oct 15, 2025
Updated
Nov 4, 2025
Reserved
Aug 6, 2025

Read the record on cve.org

Description

This issue affects Apache Spark versions before 3.4.4, 3.5.2 and 4.0.0.

Apache Spark versions before 4.0.0, 3.5.2 and 3.4.4 use an insecure default network encryption cipher for RPC communication between nodes.

When spark.network.crypto.enabled is set to true (it is set to false by default), but spark.network.crypto.cipher is not explicitly configured, Spark defaults to AES in CTR mode (AES/CTR/NoPadding), which provides encryption without authentication.

This vulnerability allows a man-in-the-middle attacker to modify encrypted RPC traffic undetected by flipping bits in ciphertext, potentially compromising heartbeat messages or application data and affecting the integrity of Spark workflows.

To mitigate this issue, users should either configure spark.network.crypto.cipher to AES/GCM/NoPadding to enable authenticated encryption or

enable SSL encryption by setting spark.ssl.enabled to true, which provides stronger transport security.

Scores

CVSSScoreVectorSource
3.16.5 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:NCISA-ADP

Weaknesses

  • CWE-347 Improper Verification of Cryptographic Signature
  • CWE-326 Inadequate Encryption Strength

Affected Products

ProductVersions
Apache SparkApache Software Foundation
  • 3.5.0 to before 3.5.2Affected
  • before 3.4.4Affected
Apache SparkApache Software Foundation
  • 3.5.0 to before 3.5.2Affected
  • before 3.4.4Affected

References

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