CVE-2022-50237: Ed25519 dalek `ed25519-dalek` Double Public Key Signing Vulnerability

MODERATE
Advisory Identifier: GHSA-w5vr-6qhr-36cc
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CVSS 5.9
CWE-497
Published
Advisory Summary

CVE-2022-50237 is a MODERATE (CVSS 5.9) `ed25519-dalek` double public key signing vulnerability (CWE-497: Exposure of Sensitive System Information to an Unauthorized Control Sphere) affecting Ed25519 dalek libraries in the crates.io ecosystem. The issue involves `ed25519-dalek` double public key signing function oracle attack. Remediation is available by upgrading affected packages to version 2.0.0.

CVE-2022-50237 at a Glance

CVE Identifier CVE-2022-50237
GHSA Identifier GHSA-w5vr-6qhr-36cc
Severity MODERATE
CVSS v3.1 Base Score 5.9
CWE Classification CWE-497: Exposure of Sensitive System Information to an Unauthorized Control Sphere
Affected Product Ed25519 dalek
Package Ecosystem crates.io
Published Date
Last Updated

Security Impact

CVSS: 5.9

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N).

Attack Vector Local (AV:L)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Changed (S:C)
Confidentiality High (C:H)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2022-50237

To remediate this vulnerability, upgrade all affected Ed25519 dalek dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

ed25519-dalek fixed: 2.0.0 
Upgrade ed25519-dalek to 2.0.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for ed25519-dalek

How to Check if You Are Affected

To determine whether your application is affected by CVE-2022-50237, inspect your project dependencies for Ed25519 dalek:

inspect dependencies for ed25519-dalek

Analyze the terminal output to locate any version of Ed25519 dalek in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.0.0), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-497: Exposure of Sensitive System Information to an Unauthorized Control Sphere, where the product does not properly prevent sensitive system-level information from being accessed by unauthorized actors who do not have the same level of access to the underlying system as the product does. In Ed25519 dalek, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

Versions of `ed25519-dalek` prior to v2.0 model private and public keys as separate types which can be assembled into a `Keypair`, and also provide APIs for serializing and deserializing 64-byte private/public keypairs. Such APIs and serializations are inherently unsafe as the public key is one of the inputs used in the deterministic computation of the `S` part of the signature, but not in the `R` value. An adversary could somehow use the signing function as an oracle that allows arbitrary public keys as input can obtain two signatures for the same message sharing the same `R` and only differ on the `S` part. Unfortunately, when this happens, one can easily extract the private key. Revised public APIs in v2.0 of `ed25519-dalek` do NOT allow a decoupled private/public keypair as signing input, except as part of specially labeled "hazmat" APIs which are clearly labeled as being dangerous if misused.

CVE-2022-50237 Affected Ed25519 dalek Versions

1 component(s)
Fixed Versions:
2.0.0
Product / Package Ecosystem Affected Versions Fixed Version
ed25519-dalek
 crates.io
< 2.0.0
2.0.0

References

NVD — CVE-2022-50237 NVD
https://nvd.nist.gov/vuln/detail/CVE-2022-50237
Ed25519 dalek Source Repository REPOSITORY
https://github.com/MystenLabs/ed25519-unsafe-libs
Ed25519 dalek Source Repository REPOSITORY
https://github.com/dalek-cryptography/ed25519-dalek
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2022-0093.html

Frequently Asked Questions

What is CVE-2022-50237?
CVE-2022-50237 is a security vulnerability in Ed25519 dalek involving `ed25519-dalek` Double Public Key Signing Function Oracle Attack under CWE-497: Exposure of Sensitive System Information to an Unauthorized Control Sphere.
Which Ed25519 dalek versions are affected?
Affected versions include releases prior to 2.0.0 across affected packages: ed25519-dalek.
What version fixes CVE-2022-50237?
Upgrading to 2.0.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is ed25519-dalek affected?
Yes, ed25519-dalek is affected in releases prior to 2.0.0. Upgrade your dependency to 2.0.0 or later.
What is the CVSS score of CVE-2022-50237?
CVE-2022-50237 has a CVSS v3.1 base score of 5.9 (MODERATE) with vector string CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N.
What CWE is associated with CVE-2022-50237?
CVE-2022-50237 is classified under CWE-497: Exposure of Sensitive System Information to an Unauthorized Control Sphere (The product does not properly prevent sensitive system-level information from being accessed by unauthorized actors who do not have the same level of access to the underlying system as the product does.).
How can I check crates.io dependencies for CVE-2022-50237?
Run the dependency tree command: 'inspect dependencies for ed25519-dalek'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-w5vr-6qhr-36cc",
  "modified" : "2025-07-28T15:53:32Z",
  "published" : "2023-08-14T21:10:29Z",
  "aliases" : [ "CVE-2022-50237" ],
  "summary" : "`ed25519-dalek` Double Public Key Signing Function Oracle Attack",
  "details" : "Versions of `ed25519-dalek` prior to v2.0 model private and public keys as separate types which can be assembled into a `Keypair`, and also provide APIs for serializing and deserializing 64-byte private/public keypairs.\n\nSuch APIs and serializations are inherently unsafe as the public key is one of the inputs used in the deterministic computation of the `S` part of the signature, but not in the `R` value. An adversary could somehow use the signing function as an oracle that allows arbitrary public keys as input can obtain two signatures for the same message sharing the same `R` and only differ on the `S` part.\n\nUnfortunately, when this happens, one can easily extract the private key.\n\nRevised public APIs in v2.0 of `ed25519-dalek` do NOT allow a decoupled private/public keypair as signing input, except as part of specially labeled \"hazmat\" APIs which are clearly labeled as being dangerous if misused.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "ed25519-dalek"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.0.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2022-50237"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/MystenLabs/ed25519-unsafe-libs"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/dalek-cryptography/ed25519-dalek"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2022-0093.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-497" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-08-14T21:10:29Z",
    "nvd_published_at" : null
  }
}