CVE-2023-49092: Marvin Attack Potential Key Recovery Through Timing Vulnerability

MODERATE
Advisory Identifier: GHSA-c38w-74pg-36hr
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CVSS 5.9
CWE-203 CWE-385
Published
Advisory Summary

CVE-2023-49092 is a MODERATE (CVSS 5.9) potential key recovery through timing vulnerability (CWE-203: Observable Discrepancy) 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.

CVE-2023-49092 at a Glance

CVE Identifier CVE-2023-49092
GHSA Identifier GHSA-c38w-74pg-36hr
Severity MODERATE
CVSS v3.1 Base Score 5.9
CWE Classification CWE-203: Observable Discrepancy
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 CVE-2023-49092

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 CVE-2023-49092, 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-203: Observable Discrepancy, where the product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor. 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

### Impact Due to a non-constant-time implementation, information about the private key is leaked through timing information which is observable over the network. An attacker may be able to use that information to recover the key. ### Patches No patch is yet available, however work is underway to migrate to a fully constant-time implementation. ### Workarounds The only currently available workaround is to avoid using the `rsa` crate in settings where attackers are able to observe timing information, e.g. local use on a non-compromised computer is fine. ### References This vulnerability was discovered as part of the "Marvin Attack", which revealed several implementations of RSA including OpenSSL had not properly mitigated timing sidechannel attacks. - https://rustsec.org/advisories/RUSTSEC-2023-0071.html - https://people.redhat.com/~hkario/marvin/ - https://github.com/RustCrypto/RSA/issues/19

CVE-2023-49092 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
NVD — CVE-2023-49092 NVD
https://nvd.nist.gov/vuln/detail/CVE-2023-49092
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 CVE-2023-49092?
CVE-2023-49092 is a security vulnerability in Marvin Attack involving potential key recovery through timing sidechannels under CWE-203: Observable Discrepancy.
Which Marvin Attack versions are affected?
Affected versions include releases prior to current release patches across affected packages: rsa.
What version fixes CVE-2023-49092?
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 CVE-2023-49092?
CVE-2023-49092 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 CVE-2023-49092?
CVE-2023-49092 is classified under CWE-203: Observable Discrepancy (The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor.).
How can I check crates.io dependencies for CVE-2023-49092?
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-c38w-74pg-36hr",
  "modified" : "2026-04-27T16:45:08Z",
  "published" : "2023-11-28T23:28:27Z",
  "aliases" : [ "CVE-2023-49092" ],
  "summary" : "Marvin Attack: potential key recovery through timing sidechannels",
  "details" : "### Impact\nDue to a non-constant-time implementation, information about the private key is leaked through timing information which is observable over the network. An attacker may be able to use that information to recover the key.\n\n### Patches\nNo patch is yet available, however work is underway to migrate to a fully constant-time implementation.\n\n### Workarounds\nThe only currently available workaround is to avoid using the `rsa` crate in settings where attackers are able to observe timing information, e.g. local use on a non-compromised computer is fine.\n\n### References\nThis vulnerability was discovered as part of the \"Marvin Attack\", which revealed several implementations of RSA including OpenSSL had not properly mitigated timing sidechannel attacks.\n\n- https://rustsec.org/advisories/RUSTSEC-2023-0071.html\n- https://people.redhat.com/~hkario/marvin/\n- https://github.com/RustCrypto/RSA/issues/19",
  "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" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2023-49092"
  }, {
    "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-203", "CWE-385" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-11-28T23:28:27Z",
    "nvd_published_at" : "2023-11-28T21:15:08Z"
  }
}