CVE-2020-25658

Severity: medium (CVSS 5.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.7% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2020-11-12 · updated 2026-06-17
Weakness: CWE-385

Description

It was found that python-rsa is vulnerable to Bleichenbacher timing attacks. An attacker can use this flaw via the RSA decryption API to decrypt parts of the cipher text encrypted with RSA.

Affected products

Fedoraproject Fedora: 33, 34, 35
Python-Rsa Project Python-Rsa: from 2.1 before 4.7 — fixed in 4.7
nova_libvirt container provided by the Red Hat OpenStack Platform: 13.0, 16.0

How to fix

Upgrade to a fixed version: Python-Rsa Project Python-Rsa 4.7. Check the vendor advisory for mitigations.

References

https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-25658
https://github.com/sybrenstuvel/python-rsa/issues/165
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2SAF67KDGSOHLVFTRDOHNEAFDRSSYIWA/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/APF364QJ2IYLPDNVFBOEJ24QP2WLVLJP/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QY4PJWTYSOV7ZEYZVMYIF6XRU73CY6O7/
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-25658
https://github.com/sybrenstuvel/python-rsa/issues/165
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2SAF67KDGSOHLVFTRDOHNEAFDRSSYIWA/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/APF364QJ2IYLPDNVFBOEJ24QP2WLVLJP/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QY4PJWTYSOV7ZEYZVMYIF6XRU73CY6O7/

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