GHSA-4grx-2x9w-596c: Marvin Attack Potential Key Recovery Through Timing Vulnerability

MODERATE
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CVSS 5.9
CWE-385
Published
Advisory Summary

GHSA-4grx-2x9w-596c is a MODERATE (CVSS 5.9) potential key recovery through timing vulnerability (CWE-385: Covert Timing Channel) affecting Marvin Attack libraries in the crates.io ecosystem. The issue involves potential key recovery through timing sidechannels. Remediation is available in the latest vendor maintenance releases.

GHSA-4grx-2x9w-596c at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-4grx-2x9w-596c
Severity MODERATE
CVSS v3.1 Base Score 5.9
CWE Classification CWE-385: Covert Timing Channel
Affected Product Marvin Attack
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:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N).

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

How to Fix GHSA-4grx-2x9w-596c

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

rsa fixed: Latest secure release 
Upgrade rsa to Latest secure release
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 rsa

How to Check if You Are Affected

To determine whether your application is affected by GHSA-4grx-2x9w-596c, inspect your project dependencies for Marvin Attack:

inspect dependencies for rsa

Analyze the terminal output to locate any version of Marvin Attack in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), 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-385: Covert Timing Channel, where covert timing channels convey information by modulating some aspect of system behavior over time, so that the program receiving the information can observe system behavior and infer protected information. In Marvin Attack, 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

The [Marvin Attack] is a timing sidechannel vulnerability which allows performing RSA decryption and signing operations as an attacker with the ability to observe only the time of the decryption operation performed withthe private key. A recent survey of RSA implementations found that the Rust `rsa` crate is one of many implementations vulnerable to this attack. No fixed version is available at this time. [Marvin Attack]: https://people.redhat.com/~hkario/marvin/

GHSA-4grx-2x9w-596c Affected Marvin Attack Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
rsa
 crates.io
≤ 0.9.6

References

GitHub Advisory / Wiki ADVISORY
https://github.com/RustCrypto/RSA/security/advisories/GHSA-c38w-74pg-36hr
Marvin Attack Source Repository REPOSITORY
https://github.com/RustCrypto/RSA/issues/19#issuecomment-1822995643
Marvin Attack Source Repository REPOSITORY
https://github.com/RustCrypto/RSA/issues/626
Marvin Attack Source Repository REPOSITORY
https://github.com/RustCrypto/RSA
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2023-0071.html

Frequently Asked Questions

What is GHSA-4grx-2x9w-596c?
GHSA-4grx-2x9w-596c is a security vulnerability in Marvin Attack involving potential key recovery through timing sidechannels under CWE-385: Covert Timing Channel.
Which Marvin Attack versions are affected?
Affected versions include releases prior to current release patches across affected packages: rsa.
What version fixes GHSA-4grx-2x9w-596c?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is rsa affected?
Yes, rsa is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of GHSA-4grx-2x9w-596c?
GHSA-4grx-2x9w-596c has a CVSS v3.1 base score of 5.9 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.
What CWE is associated with GHSA-4grx-2x9w-596c?
GHSA-4grx-2x9w-596c is classified under CWE-385: Covert Timing Channel (Covert timing channels convey information by modulating some aspect of system behavior over time, so that the program receiving the information can observe system behavior and infer protected information.).
How can I check crates.io dependencies for GHSA-4grx-2x9w-596c?
Run the dependency tree command: 'inspect dependencies for rsa'. 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-4grx-2x9w-596c",
  "modified" : "2026-05-04T20:43:22Z",
  "published" : "2023-11-28T23:28:25Z",
  "aliases" : [ ],
  "summary" : "Marvin Attack: potential key recovery through timing sidechannels",
  "details" : "The [Marvin Attack] is a timing sidechannel vulnerability which allows performing RSA decryption and signing operations as an attacker with the ability to observe only the time of the decryption operation performed withthe private key.\n\nA recent survey of RSA implementations found that the Rust `rsa` crate is one of many implementations vulnerable to this attack.\n\nNo fixed version is available at this time.\n\n[Marvin Attack]: https://people.redhat.com/~hkario/marvin/",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "rsa"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "0.9.6"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/RustCrypto/RSA/security/advisories/GHSA-c38w-74pg-36hr"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/RustCrypto/RSA/issues/19#issuecomment-1822995643"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/RustCrypto/RSA/issues/626"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/RustCrypto/RSA"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2023-0071.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-385" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-11-28T23:28:25Z",
    "nvd_published_at" : null
  }
}