CVE-2022-4304Network attack vector

RSA plaintext recovery via decryption timing oracle

Published Feb 8, 2023 · Updated Nov 4, 2025

Observable timing discrepancy in OpenSSL 1.0.2, 1.1.1, and 3.0 allows remote attackers to recover RSA plaintext across a network. RSA decryption takes input-dependent time across PKCS#1 v1.5, RSA-OAEP, and RSASVE padding paths, creating a Bleichenbacher oracle. Exploitation requires observing a genuine connection and sending a very large number of trial ciphertexts; success exposes that session's application data.

CVSS severity5.9
Medium
EPSS probability16.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Observable timing discrepancy in OpenSSL 1.0.2, 1.1.1, and 3.0 allows remote attackers to recover RSA plaintext across a network. RSA decryption takes input-dependent time across PKCS#1 v1.5, RSA-OAEP, and RSASVE padding paths, creating a Bleichenbacher oracle. Exploitation requires observing a genuine connection and sending a very large number of trial ciphertexts; success exposes that session's application data.

The record

CVE
CVE-2022-4304
Published
Feb 8, 2023
Updated
Nov 4, 2025
Vendor
OpenSSL Project
Product
OpenSSL
Classifications
CWE-203, T1040
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 8, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 4, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.0.2 <1.0.2zg
  2. Affected versionversion=1.1.1 <1.1.1t
  3. Affected versionversion=3.0.0 <3.0.8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

OpenSSL Project · OpenSSLversion=1.0.2 <1.0.2zg; version=1.1.1 <1.1.1t; version=3.0.0 <3.0.8

Published CVSS scores

5.9NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
5.9CISA-ADPCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-203Observable Discrepancy
T1040Network Sniffing

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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