CVE-2023-28113Public exploitNetwork attack vector

Session eavesdropping via unchecked Diffie-Hellman keys

Published Mar 16, 2023 · Updated Feb 25, 2025

Improper key validation in russh 0.34.0 through 0.36.1 and 0.37.0 allows remote attackers to eavesdrop on SSH sessions. The finite-field DH key-exchange path accepts peer public values outside 1 < value < p-1 and can generate private exponents outside required bounds, producing predictable or low-order shared secrets. An unauthenticated malicious SSH peer must negotiate a finite-field Diffie-Hellman exchange; ordinary peers usually reject the invalid values, limiting practical exposure mainly to russh-to-russh or deliberately misbehaving-peer connections.

CVSS severity5.9
Medium
EPSS probability0.63%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper key validation in russh 0.34.0 through 0.36.1 and 0.37.0 allows remote attackers to eavesdrop on SSH sessions. The finite-field DH key-exchange path accepts peer public values outside 1 < value < p-1 and can generate private exponents outside required bounds, producing predictable or low-order shared secrets. An unauthenticated malicious SSH peer must negotiate a finite-field Diffie-Hellman exchange; ordinary peers usually reject the invalid values, limiting practical exposure mainly to russh-to-russh or deliberately misbehaving-peer connections.

The record

CVE
CVE-2023-28113
Published
Mar 16, 2023
Updated
Feb 25, 2025
Vendor
Russh Project
Product
russh
Classifications
CWE-347, CWE-20, CWE-358, T1040
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 16, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 25, 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=0.34.0 <0.34.0*
  2. Affected versionversion=0.36.2 <0.36.2
  3. Affected versionversion=0.37.0 <0.37.0*
  4. Affected versionversion=0.37.1 <0.37.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Russh Project · russhversion=0.34.0 <0.34.0*; version=0.36.2 <0.36.2; version=0.37.0 <0.37.0*; version=0.37.1 <0.37.1

Published CVSS scores

5.9GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-347Improper Verification of Cryptographic Signature
CWE-20Improper Input Validation
CWE-358Improperly Implemented Security Check for Standard
T1040Network Sniffing

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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