Marvin Attack: potential key recovery through timing sidechannels

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.9 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS

• CVE-2023-49092: 0.61% estimated exploitation activity in the next 30 days; percentile 49.27 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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

Published by the source

28 Nov 2023, 23:28 UTC

Last modified by the source

27 Apr 2026, 16:45 UTC

Source last checked

26 Oct 2026, 15:42 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-c38w-74pg-36hr

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# Patch Next advisory brief: CVE-2023-49092

Advisory: Marvin Attack: potential key recovery through timing sidechannels
IDs: CVE-2023-49092, GHSA-c38w-74pg-36hr
Record: https://patchnext.com/advisories/cve-2023-49092 (revision 1, source checked 26 Oct 2026, 15:42 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io rsa: affected <= 0.9.6

## Suggested inspection (read-only)
- crates.io rsa: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on rsa.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-c38w-74pg-36hr (GitHub-reviewed advisory GHSA-c38w-74pg-36hr lists affected ranges: crates.io rsa >=0 <=0.9.6)

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