#VU73108 Covert Timing Channel in python-rsa - CVE-2020-25658

Vulnerability identifier: #VU73108

Vulnerability risk: Low

CVSSv4.0: 1.7 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2020-25658

CWE-ID: CWE-385

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
python-rsa
Other software / Other software solutions

Vendor: sybrenstuvel

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

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External links
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/APF364QJ2IYLPDNVFBOEJ24QP2WLVLJP/
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/QY4PJWTYSOV7ZEYZVMYIF6XRU73CY6O7/

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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.