Bleichenbacher timing attack in python-rsa

1) Covert Timing Channel

EUVDB-ID: #VU73108

Risk: Low

CVSSv3.1: 3.2 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-25658

CWE-ID: CWE-385 - Covert Timing Channel

Exploit availability: No

Description

The vulnerability allows a remote attacker to gain access to sensitive information.

The vulnerability exists due to a covert timing channel. A remote attacker can perform Bleichenbacher timing attack and decrypt parts of data via the RSA decryption API.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

python-rsa: 3.0 - 4.6

External links

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

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.