CVE-2020-9283Public exploitNetwork attack vector

SSH peer crash via malformed Ed25519 public key

Published Feb 20, 2020 · Updated Aug 4, 2024

Denial of service in golang.org/x/crypto/ssh before 0.0.0-20200220183623-bac4c82f6975 allows remote attackers to crash SSH clients or servers. The key parser and verifier pass an Ed25519 public key of unchecked length to ed25519.Verify, which panics instead of returning an error. An SSH server is exposed when it accepts public keys through PublicKeyCallback, while any SSH client is exposed to a malicious server; the bounded consequence is a process crash and service interruption.

CVSS severity7.5
High
EPSS probability20.52%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in golang.org/x/crypto/ssh before 0.0.0-20200220183623-bac4c82f6975 allows remote attackers to crash SSH clients or servers. The key parser and verifier pass an Ed25519 public key of unchecked length to ed25519.Verify, which panics instead of returning an error. An SSH server is exposed when it accepts public keys through PublicKeyCallback, while any SSH client is exposed to a malicious server; the bounded consequence is a process crash and service interruption.

The record

CVE
CVE-2020-9283
Published
Feb 20, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-347, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 20, 2020CVE 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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 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 exploitPublished

Weakness, pattern, technique

CWE-347Improper Verification of Cryptographic Signature
T1499.004Endpoint Denial of Service: Application or System Exploitation

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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