CVE-2023-50781: M2crypto: bleichenbacher timing attacks in the rsa decryption api - incomplete fix for cve-2020-25657

Published Dec 13, 2023
·
Updated

A flaw was found in m2crypto. This issue may allow a remote attacker to decrypt captured messages in TLS servers that use RSA key exchanges, which may lead to exposure of confidential or sensitive data.

Other sources

Description: The fix for CVE-2020-25657 is not addressing the leakage in the RSA decryption. Because of the API design, the fix is generally not believed to be possible to be fully addressed. The issue can be mitigated by using a cryptographic backend that implements implicit rejection (Marvin workaround). Only applications that use RSA decryption with PKCS#1 v1.5 padding are affected.

References: https://gitlab.com/m2crypto/m2crypto/-/issues/342 https://people.redhat.com/~hkario/marvin/ https://github.com/openssl/openssl/pull/13817

Red Hat

Affected Software

5 affected components
pip/m2crypto<=0.40.1
redhat Enterprise Linux=8.0
redhat Enterprise Linux=9.0
redhat Update Infrastructure=4
M2crypto Project M2crypto

Event History

Dec 13, 2023
Data Sourced
via Red Hat·09:20 PM
DescriptionSeverityAffected Software
Feb 5, 2024
CVE Published
via MITRE·08:45 PM
Data Sourced
via MITRE·08:45 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·09:15 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·09:15 PM
Affected Software
Advisory Published
via GitHub·09:30 PM
Free Weekly Intel

Don't miss critical vulnerabilities

Join thousands of security professionals who receive our weekly digest of trending CVEs, zero-days, and exploited vulnerabilities.

No spam. Unsubscribe anytime.

Frequently Asked Questions

1

What is the severity of CVE-2023-50781?

CVE-2023-50781 is classified as a critical vulnerability due to its potential to allow remote attackers to decrypt sensitive data.

2

How do I fix CVE-2023-50781?

To mitigate CVE-2023-50781, update m2crypto to a version higher than 0.40.1 immediately.

3

Which systems are affected by CVE-2023-50781?

CVE-2023-50781 affects m2crypto versions up to and including 0.40.1 on Red Hat Enterprise Linux 8.0, 9.0, and Red Hat Update Infrastructure 4.

4

Can CVE-2023-50781 lead to data breaches?

Yes, CVE-2023-50781 could potentially lead to data breaches by allowing attackers to decrypt messages in TLS servers using RSA key exchanges.

5

What should I do if I cannot update due to compatibility issues related to CVE-2023-50781?

If unable to update due to compatibility issues, evaluate potential workarounds such as using alternative cryptographic libraries while seeking a permanent fix.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203