#VU50367 Covert Timing Channel in python-cryptography

Published: 2021-01-11 | Updated: 2021-02-04

Vulnerability identifier: #VU50367

Vulnerability risk: Medium

CVSSv3.1: 5.2 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-25659


Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Universal components / Libraries / Programming Languages & Components

Vendor: Python Cryptographic Authority


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

python-cryptography 3.2 is vulnerable to Bleichenbacher timing attacks in the RSA decryption API, via timed processing of valid PKCS#1 v1.5 ciphertext.

Install update from vendor's website.

Vulnerable software versions

python-cryptography: 3.2

External links

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.

Latest bulletins with this vulnerability