CVE-2015-20112

Plaintext disclosure via AES-CTR keystream reuse

Published Jun 29, 2025 · Updated Jun 30, 2025

Cryptographic key reuse in Ethereum Foundation RLPx 5 allows man-in-the-middle attackers to decrypt private-network traffic. The framing layer initializes both directional AES-CTR streams with the same secret, nonce, and IV, so known plaintext reveals the reused keystream for opposite-direction ciphertext. Exploitation requires a private-network position and known plaintext; the documented consequence is message confidentiality loss, not modification or service interruption.

CVSS severity3.4
Low
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cryptographic key reuse in Ethereum Foundation RLPx 5 allows man-in-the-middle attackers to decrypt private-network traffic. The framing layer initializes both directional AES-CTR streams with the same secret, nonce, and IV, so known plaintext reveals the reused keystream for opposite-direction ciphertext. Exploitation requires a private-network position and known plaintext; the documented consequence is message confidentiality loss, not modification or service interruption.

The record

CVE
CVE-2015-20112
Published
Jun 29, 2025
Updated
Jun 30, 2025
Vendor
Ethereum Foundation
Product
RLPx
Classifications
CWE-325, T1040
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 29, 2025CVE publishedPublication date reported by the CVE source.
  2. Jun 30, 2025Record 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=5

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Ethereum Foundation · RLPxversion=5

Published CVSS scores

3.4MITRECVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:L/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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-325Missing Cryptographic Step
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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