CVE-2023-50781Network attack vector

TLS plaintext disclosure via RSA timing oracle

Published Feb 5, 2024 · Updated May 12, 2026

Timing side channel in M2Crypto 0.40.1 and earlier allows remote attackers to decrypt captured TLS messages using RSA key exchange. The RSA decryption API handles PKCS#1 v1.5 padding failures with observably different timing, leaving the earlier mitigation incomplete. Exploitation requires a TLS server that calls this path and permits repeated oracle queries; the bounded impact is disclosure of captured plaintext.

CVSS severity7.5
High
EPSS probability1.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Timing side channel in M2Crypto 0.40.1 and earlier allows remote attackers to decrypt captured TLS messages using RSA key exchange. The RSA decryption API handles PKCS#1 v1.5 padding failures with observably different timing, leaving the earlier mitigation incomplete. Exploitation requires a TLS server that calls this path and permits repeated oracle queries; the bounded impact is disclosure of captured plaintext.

The record

CVE
CVE-2023-50781
Published
Feb 5, 2024
Updated
May 12, 2026
Vendor
Red Hat
Product
Red Hat Update Infrastructure
Classifications
CWE-327, CWE-203, T1040
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 5, 2024CVE publishedPublication date reported by the CVE source.
  2. May 12, 2026Record 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?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Red Hat · Red Hat Update InfrastructureAffected versions are unavailable in this record.
Siemens · SIMATIC S7-1500 TM MFP - GNU/Linux subsystemversion=0 <*
M2Crypto Project · M2CryptoAffected versions are unavailable in this record.

Published CVSS scores

7.5Siemens ProductCERTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
7.5Red HatCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
5.9GitHub Advisory DatabaseCVSS: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-327Use of a Broken or Risky Cryptographic Algorithm
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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