CVE Vulnerabilities

CVE-2020-25659

Covert Timing Channel

Published: Jan 11, 2021 | Modified: Nov 21, 2024
CVSS 3.x
5.9
MEDIUM
Source:
NVD
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS 2.x
4.3 MEDIUM
AV:N/AC:M/Au:N/C:P/I:N/A:N
RedHat/V2
RedHat/V3
5.9 MODERATE
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Ubuntu
MEDIUM

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.

Weakness

Covert timing channels convey information by modulating some aspect of system behavior over time, so that the program receiving the information can observe system behavior and infer protected information.

Affected Software

Name Vendor Start Version End Version
Cryptography Cryptography.io 3.2 (including) 3.2 (including)
Red Hat Enterprise Linux 8 RedHat python-cryptography-0:3.2.1-4.el8 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat rh-python38-babel-0:2.7.0-12.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat rh-python38-python-0:3.8.11-2.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat rh-python38-python-cryptography-0:2.8-5.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat rh-python38-python-jinja2-0:2.10.3-6.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat rh-python38-python-lxml-0:4.4.1-7.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat rh-python38-python-pip-0:19.3.1-2.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat rh-python38-python-urllib3-0:1.25.7-7.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS RedHat rh-python38-babel-0:2.7.0-12.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS RedHat rh-python38-python-0:3.8.11-2.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS RedHat rh-python38-python-cryptography-0:2.8-5.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS RedHat rh-python38-python-jinja2-0:2.10.3-6.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS RedHat rh-python38-python-lxml-0:4.4.1-7.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS RedHat rh-python38-python-pip-0:19.3.1-2.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS RedHat rh-python38-python-urllib3-0:1.25.7-7.el7 *
Red Hat Virtualization 4 for Red Hat Enterprise Linux 8 RedHat redhat-virtualization-host-0:4.4.6-20210527.3.el8_4 *
Python-cryptography Ubuntu bionic *
Python-cryptography Ubuntu devel *
Python-cryptography Ubuntu focal *
Python-cryptography Ubuntu groovy *
Python-cryptography Ubuntu trusty *
Python-cryptography Ubuntu upstream *
Python-cryptography Ubuntu xenial *

Extended Description

In some instances, knowing when data is transmitted between parties can provide a malicious user with privileged information. Also, externally monitoring the timing of operations can potentially reveal sensitive data. For example, a cryptographic operation can expose its internal state if the time it takes to perform the operation varies, based on the state. Covert channels are frequently classified as either storage or timing channels. Some examples of covert timing channels are the system’s paging rate, the time a certain transaction requires to execute, and the time it takes to gain access to a shared bus.

Potential Mitigations

References