Headline
New Python URL Parsing Flaw Enables Command Injection Attacks
A high-severity security flaw has been disclosed in the Python URL parsing function that could be exploited to bypass domain or protocol filtering methods implemented with a blocklist, ultimately resulting in arbitrary file reads and command execution. “urlparse has a parsing problem when the entire URL starts with blank characters,” the CERT Coordination Center (CERT/CC) said in a Friday
Programming / Vulnerability
A high-severity security flaw has been disclosed in the Python URL parsing function that could be exploited to bypass domain or protocol filtering methods implemented with a blocklist, ultimately resulting in arbitrary file reads and command execution.
“urlparse has a parsing problem when the entire URL starts with blank characters,” the CERT Coordination Center (CERT/CC) said in a Friday advisory. “This problem affects both the parsing of hostname and scheme, and eventually causes any blocklisting methods to fail.”
The flaw has been assigned the identifier CVE-2023-24329 and carries a CVSS score of 7.5. Security researcher Yebo Cao has been credited with discovering and reporting the issue in August 2022. It has been addressed in the following versions -
- >= 3.12
- 3.11.x >= 3.11.4
- 3.10.x >= 3.10.12
- 3.9.x >= 3.9.17
- 3.8.x >= 3.8.17, and
- 3.7.x >= 3.7.17
urllib.parse is a widely used parsing function that makes it possible to break down URLs to its constituents, or alternatively, combine the components to a URL string.
CVE-2023-24329 arises as a result of a lack of input validation, thereby leading to a scenario where it’s possible to get around blocklisting methods by supplying a URL that starts with blank characters (e.g., " https://youtube[.]com").
“Although blocklist is considered an inferior choice, there are many scenarios where blocklist is still needed,” Cao said. “This vulnerability would help an attacker to bypass the protections set by the developer for scheme and host. This vulnerability can be expected to help SSRF and RCE in a wide range of scenarios.”
Found this article interesting? Follow us on Twitter and LinkedIn to read more exclusive content we post.
Related news
Red Hat Security Advisory 2023-4875-01 - Red Hat Advanced Cluster Management for Kubernetes 2.8.1 images Red Hat Advanced Cluster Management for Kubernetes provides the capabilities to address common challenges that administrators and site reliability engineers face as they work across a range of public and private cloud environments. Clusters and applications are all visible and managed from a single console—with security policy built in. This advisory contains the container images for Red Hat Advanced Cluster Management for Kubernetes, which provide security updates and fix several bugs. Issues addressed include bypass and privilege escalation vulnerabilities.
Red Hat OpenShift Container Platform release 4.11.46 is now available with updates to packages and images that fix several bugs and add enhancements. This release includes a security update for Red Hat OpenShift Container Platform 4.11. Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original. Related CVEs: * CVE-2021-38561: A flaw was found in golang. The language package for go language can panic due to an out-of-bounds read when an incorrectly formatted language tag is being parsed. This flaw allows a...
An update for redhat-release-virtualization-host and redhat-virtualization-host is now available for Red Hat Virtualization 4 for Red Hat Enterprise Linux 8. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original. Related CVEs: * CVE-2023-24329: A flaw was found in the Python package. An issue in the urllib.parse component could allow attackers to bypass blocklisting methods by supplying a URL that starts with blank characters.This may lead to compromised Integrity.
Red Hat Security Advisory 2023-3936-01 - Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems. Issues addressed include a bypass vulnerability.
An update for python3 is now available for Red Hat Enterprise Linux 8.2 Advanced Update Support, Red Hat Enterprise Linux 8.2 Telecommunications Update Service, and Red Hat Enterprise Linux 8.2 Update Services for SAP Solutions. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original. Related CVEs: * CVE-2023-24329: A flaw was found in the Python package. An issue in the urllib.parse component could allow attackers to bypass blocklisting methods by supplying a URL that starts with blank characters.This...
An update for python3 is now available for Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support, Red Hat Enterprise Linux 8.4 Telecommunications Update Service, and Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original. Related CVEs: * CVE-2023-24329: A flaw was found in the Python package. An issue in the urllib.parse component could allow attackers to bypass blocklisting methods by supplying a URL that starts with blan...
Red Hat Security Advisory 2023-3614-01 - Red Hat OpenShift Container Platform is Red Hat's cloud computing Kubernetes application platform solution designed for on-premise or private cloud deployments. This advisory contains the container images for Red Hat OpenShift Container Platform 4.13.4.
Red Hat Security Advisory 2023-3777-01 - Python is an interpreted, interactive, object-oriented programming language that supports modules, classes, exceptions, high-level dynamic data types, and dynamic typing. The python27 packages provide a stable release of Python 2.7 with a number of additional utilities and database connectors for MySQL and PostgreSQL. Issues addressed include a bypass vulnerability.
Red Hat Security Advisory 2023-3776-01 - Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems. Issues addressed include a bypass vulnerability.
Red Hat Security Advisory 2023-3556-01 - Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems. Issues addressed include a bypass vulnerability.
Ubuntu Security Notice 5960-1 - Yebo Cao discovered that Python incorrectly handled certain URLs. An attacker could possibly use this issue to bypass blocklisting methods by supplying a URL that starts with blank characters.