CVE Vulnerabilities

CVE-2020-8492

Uncontrolled Resource Consumption

Published: Jan 30, 2020 | Modified: Nov 21, 2024
CVSS 3.x
6.5
MEDIUM
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
CVSS 2.x
7.1 HIGH
AV:N/AC:M/Au:N/C:N/I:N/A:C
RedHat/V2
RedHat/V3
6.5 MODERATE
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Ubuntu
LOW

Python 2.7 through 2.7.17, 3.5 through 3.5.9, 3.6 through 3.6.10, 3.7 through 3.7.6, and 3.8 through 3.8.1 allows an HTTP server to conduct Regular Expression Denial of Service (ReDoS) attacks against a client because of urllib.request.AbstractBasicAuthHandler catastrophic backtracking.

Weakness

The product does not properly control the allocation and maintenance of a limited resource.

Affected Software

Name Vendor Start Version End Version
Python Python 2.7.0 (including) 2.7.17 (including)
Python Python 3.5.0 (including) 3.5.9 (including)
Python Python 3.6.0 (including) 3.6.10 (including)
Python Python 3.7.0 (including) 3.7.6 (including)
Python Python 3.8.0 (including) 3.8.1 (including)
Red Hat Enterprise Linux 7 RedHat python3-0:3.6.8-17.el7 *
Red Hat Enterprise Linux 8 RedHat python3-0:3.6.8-31.el8 *
Red Hat Enterprise Linux 8 RedHat python38:3.8-8030020200818121840.4190259b *
Red Hat Enterprise Linux 8 RedHat python3-0:3.6.8-31.el8 *
Red Hat Software Collections for Red Hat Enterprise Linux 6 RedHat rh-python36-python-0:3.6.12-1.el6 *
Red Hat Software Collections for Red Hat Enterprise Linux 6 RedHat rh-python36-python-pip-0:9.0.1-5.el6 *
Red Hat Software Collections for Red Hat Enterprise Linux 6 RedHat rh-python36-python-virtualenv-0:15.1.0-3.el6 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat rh-python36-python-0:3.6.12-1.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat rh-python36-python-pip-0:9.0.1-5.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat rh-python36-python-virtualenv-0:15.1.0-3.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS RedHat rh-python36-python-0:3.6.12-1.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS RedHat rh-python36-python-pip-0:9.0.1-5.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS RedHat rh-python36-python-virtualenv-0:15.1.0-3.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS RedHat rh-python36-python-0:3.6.12-1.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS RedHat rh-python36-python-pip-0:9.0.1-5.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS RedHat rh-python36-python-virtualenv-0:15.1.0-3.el7 *
Python2.7 Ubuntu bionic *
Python2.7 Ubuntu eoan *
Python2.7 Ubuntu esm-apps/focal *
Python2.7 Ubuntu esm-infra-legacy/trusty *
Python2.7 Ubuntu esm-infra/bionic *
Python2.7 Ubuntu esm-infra/xenial *
Python2.7 Ubuntu focal *
Python2.7 Ubuntu groovy *
Python2.7 Ubuntu hirsute *
Python2.7 Ubuntu impish *
Python2.7 Ubuntu trusty *
Python2.7 Ubuntu trusty/esm *
Python2.7 Ubuntu xenial *
Python3.4 Ubuntu esm-infra-legacy/trusty *
Python3.4 Ubuntu trusty *
Python3.4 Ubuntu trusty/esm *
Python3.5 Ubuntu esm-infra-legacy/trusty *
Python3.5 Ubuntu esm-infra/xenial *
Python3.5 Ubuntu trusty *
Python3.5 Ubuntu trusty/esm *
Python3.5 Ubuntu xenial *
Python3.6 Ubuntu bionic *
Python3.6 Ubuntu esm-infra/bionic *
Python3.7 Ubuntu bionic *
Python3.7 Ubuntu eoan *
Python3.7 Ubuntu esm-apps/bionic *
Python3.8 Ubuntu bionic *
Python3.8 Ubuntu eoan *
Python3.8 Ubuntu esm-apps/bionic *
Python3.8 Ubuntu esm-infra/focal *
Python3.8 Ubuntu focal *
Python3.8 Ubuntu groovy *

Potential Mitigations

  • Mitigation of resource exhaustion attacks requires that the target system either:

  • The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.

  • The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.

References