Marvin Attack: potential key recovery through timing sidechannels (CVE-2023-49092) | HOL Guard CVE

Medium · CVSS 5.9CVE-2023-49092GHSA-4GRX-2X9W-596C

Marvin Attack: potential key recovery through timing sidechannels

Answer in brief

CVE-2023-49092 records a Medium severity (CVSS 5.9) vulnerability in Marvin Attack: potential key recovery through timing sidechannels. The current sources do not mark it as known exploited. The current feed maps rsa (crates.io). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Nov 22, 2023Updated Sep 14, 2026Source checked Sep 14, 2026First seen by HOL Sep 14, 2026Material review Sep 14, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 5.9
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

CVSS is 5.9. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps rsa (crates.io). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
rsacrates.io	>=0.0.0-0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for rsa.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Nov 22, 2023
Evidence: source:osv:source_dates:source-dates:record
Source modified
Sep 14, 2026
Evidence: source:osv:source_dates:source-dates:record
First seen by HOL
Sep 14, 2026

Sources and claim methodology

Upstream source description

### 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. The crypto-bigint migration ([RustCrypto/RSA#394](https://github.com/RustCrypto/RSA/pull/394)) did not close this. Tracking is [RustCrypto/RSA#626](https://github.com/RustCrypto/RSA/issues/626) (padding still not constant-time). Implicit rejection work is in [RustCrypto/RSA#680](https://github.com/RustCrypto/RSA/pull/680); default-path blinding is in [RustCrypto/RSA#702](https://github.com/RustCrypto/RSA/pull/702). Still affected as of 2026-09-12: rsa 0.9.10 (latest stable) and rsa 0.10.0-rc.18 (latest). `patched = []` is intentional. ### Workarounds Avoid using the `rsa` crate in settings where attackers can observe timing, for example over the network. 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. [Marvin Attack]: https://people.redhat.com/~hkario/marvin/

Quoted source text, attributed separately from HOL analysis.