CVE-2021-33503

An issue was discovered in urllib3 before 1.26.5. When provided with a URL containing many @ characters in the authority component, the authority regular expression exhibits catastrophic backtracking, causing a denial of service if a URL were passed as a parameter or redirected to via an HTTP redirect.

Impact

When provided with a URL containing many @ characters in the authority component the authority regular expression exhibits catastrophic backtracking causing a denial of service if a URL were passed as a parameter or redirected to via an HTTP redirect.

Patches

The issue has been fixed in urllib3 v1.26.5.

References

• CVE-2021-33503
• JVNVU#92413403 (English)
• JVNVU#92413403 (Japanese)
• urllib3 v1.26.5

For more information

If you have any questions or comments about this advisory:

• Ask in our community Discord
• Email [email protected]

Security Fix(es):

An issue was discovered in urllib3 before 1.26.5. When provided with a URL containing many @ characters in the authority component, the authority regular expression exhibits catastrophic backtracking, causing a denial of service if a URL were passed as a parameter or redirected to via an HTTP redirect.(CVE-2021-33503)

pip is the package installer for Python. You can use pip to install packages from the Python Package Index and other indexes. %global bashcompdir %(b=$(pkg-config --variable=completionsdir bash-completion 2>/dev/null); echo ${b:-/bash_completion.d}) Name: python-pip Version: 21.3.1 Release: 1 Summary: A tool for installing and managing Python packages License: MIT and Python and ASL 2.0 and BSD and ISC and LGPLv2 and MPLv2.0 and (ASL 2.0 or BSD) URL: http://www.pip-installer.org Source0: BuildArch: noarch Patch1: allow-stripping-given-prefix-from-wheel-RECORD-files. Patch2: emit-a-warning-when-running-with-root-privileges.patch Patch6000: dummy-certifi.patch

Security Fix(es):

An issue was discovered in urllib3 before 1.26.5. When provided with a URL containing many @ characters in the authority component, the authority regular expression exhibits catastrophic backtracking, causing a denial of service if a URL were passed as a parameter or redirected to via an HTTP redirect.(CVE-2021-33503)

Lib/ipaddress.py in Python through 3.8.3 improperly computes hash values in the IPv4Interface and IPv6Interface classes, which might allow a remote attacker to cause a denial of service if an application is affected by the performance of a dictionary containing IPv4Interface or IPv6Interface objects, and this attacker can cause many dictionary entries to be created. This is fixed in: v3.5.10, v3.5.10rc1; v3.6.12; v3.7.9; v3.8.4, v3.8.4rc1, v3.8.5, v3.8.6, v3.8.6rc1; v3.9.0, v3.9.0b4, v3.9.0b5, v3.9.0rc1, v3.9.0rc2.(CVE-2020-14422)

pip is the package installer for Python. You can use pip to install packages from the Python Package Index and other indexes. %global bashcompdir %(b=$(pkg-config --variable=completionsdir bash-completion 2>/dev/null); echo ${b:-/bash_completion.d}) Name: python-pip Version: 21.3.1 Release: 1 Summary: A tool for installing and managing Python packages License: MIT and Python and ASL 2.0 and BSD and ISC and LGPLv2 and MPLv2.0 and (ASL 2.0 or BSD) URL: http://www.pip-installer.org Source0: BuildArch: noarch Patch1: allow-stripping-given-prefix-from-wheel-RECORD-files. Patch2: emit-a-warning-when-running-with-root-privileges.patch Patch6000: dummy-certifi.patch

Security Fix(es):

An issue was discovered in urllib3 before 1.26.5. When provided with a URL containing many @ characters in the authority component, the authority regular expression exhibits catastrophic backtracking, causing a denial of service if a URL were passed as a parameter or redirected to via an HTTP redirect.(CVE-2021-33503)

Lib/ipaddress.py in Python through 3.8.3 improperly computes hash values in the IPv4Interface and IPv6Interface classes, which might allow a remote attacker to cause a denial of service if an application is affected by the performance of a dictionary containing IPv4Interface or IPv6Interface objects, and this attacker can cause many dictionary entries to be created. This is fixed in: v3.5.10, v3.5.10rc1; v3.6.12; v3.7.9; v3.8.4, v3.8.4rc1, v3.8.5, v3.8.6, v3.8.6rc1; v3.9.0, v3.9.0b4, v3.9.0b5, v3.9.0rc1, v3.9.0rc2.(CVE-2020-14422)

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.

Security Fix(es):

• python: Information disclosure via pydoc (CVE-2021-3426)

• python: urllib: Regular expression DoS in AbstractBasicAuthHandler (CVE-2021-3733)

• python-lxml: Missing input sanitization for formaction HTML5 attributes may lead to XSS (CVE-2021-28957)

• python-ipaddress: Improper input validation of octal strings (CVE-2021-29921)

• python-urllib3: ReDoS in the parsing of authority part of URL (CVE-2021-33503)

• python-pip: Incorrect handling of unicode separators in git references (CVE-2021-3572)

• python: urllib: HTTP client possible infinite loop on a 100 Continue response (CVE-2021-3737)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Additional Changes:

For detailed information on changes in this release, see the Rocky Linux 8.5 Release Notes linked from the References section.

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.

Security Fix(es):

• python-psutil: Double free because of refcount mishandling (CVE-2019-18874)

• python-jinja2: ReDoS vulnerability in the urlize filter (CVE-2020-28493)

• python: Information disclosure via pydoc (CVE-2021-3426)

• python-babel: Relative path traversal allows attacker to load arbitrary locale files and execute arbitrary code (CVE-2021-20095, CVE-2021-42771)

• python: Web cache poisoning via urllib.parse.parse_qsl and urllib.parse.parse_qs by using a semicolon in query parameters (CVE-2021-23336)

• python-lxml: Missing input sanitization for formaction HTML5 attributes may lead to XSS (CVE-2021-28957)

• python-ipaddress: Improper input validation of octal strings (CVE-2021-29921)

• python-urllib3: ReDoS in the parsing of authority part of URL (CVE-2021-33503)

• python-pip: Incorrect handling of unicode separators in git references (CVE-2021-3572)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Additional Changes:

For detailed information on changes in this release, see the Rocky Linux 8.5 Release Notes linked from the References section.

An issue was discovered in urllib3 before 1.26.5. When provided with a URL containing many @ characters in the authority component, the authority regular expression exhibits catastrophic backtracking, causing a denial of service if a URL were passed as a parameter or redirected to via an HTTP redirect.

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.

Security Fix(es):

• python: Information disclosure via pydoc (CVE-2021-3426)

• python: urllib: Regular expression DoS in AbstractBasicAuthHandler (CVE-2021-3733)

• python-lxml: Missing input sanitization for formaction HTML5 attributes may lead to XSS (CVE-2021-28957)

• python-ipaddress: Improper input validation of octal strings (CVE-2021-29921)

• python-urllib3: ReDoS in the parsing of authority part of URL (CVE-2021-33503)

• python-pip: Incorrect handling of unicode separators in git references (CVE-2021-3572)

• python: urllib: HTTP client possible infinite loop on a 100 Continue response (CVE-2021-3737)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Additional Changes:

For detailed information on changes in this release, see the AlmaLinux Release Notes linked from the References section.

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.

Security Fix(es):

• python-psutil: Double free because of refcount mishandling (CVE-2019-18874)

• python-jinja2: ReDoS vulnerability in the urlize filter (CVE-2020-28493)

• python: Information disclosure via pydoc (CVE-2021-3426)

• python-babel: Relative path traversal allows attacker to load arbitrary locale files and execute arbitrary code (CVE-2021-20095, CVE-2021-42771)

• python: Web cache poisoning via urllib.parse.parse_qsl and urllib.parse.parse_qs by using a semicolon in query parameters (CVE-2021-23336)

• python-lxml: Missing input sanitization for formaction HTML5 attributes may lead to XSS (CVE-2021-28957)

• python-ipaddress: Improper input validation of octal strings (CVE-2021-29921)

• python-urllib3: ReDoS in the parsing of authority part of URL (CVE-2021-33503)

• python-pip: Incorrect handling of unicode separators in git references (CVE-2021-3572)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Additional Changes:

For detailed information on changes in this release, see the AlmaLinux Release Notes linked from the References section.

TuxCare rebuilt urllib3 to address 2 CVEs. Fixed in 1.25.11.post2+tuxcare.

TuxCare rebuilt urllib3 to address 2 CVEs. Fixed in 1.26.4.post4+tuxcare.

A flaw was found in python-pip in the way it handled Unicode separators in git references. A remote attacker could possibly use this issue to install a different revision on a repository (CVE-2021-3572).

The bundled python-urllib3 was also vulnerable to: The urllib3 library 1.26.x before 1.26.4 for Python omits SSL certificate validation in some cases involving HTTPS to HTTPS proxies. The initial connection to the HTTPS proxy (if an SSLContext isn't given via proxy_config) doesn't verify the hostname of the certificate. This means certificates for different servers that still validate properly with the default urllib3 SSLContext will be silently accepted (CVE-2021-28363).

An issue was discovered in urllib3 before 1.26.5. When provided with a URL containing many @ characters in the authority component, the authority regular expression exhibits catastrophic backtracking, causing a denial of service if a URL were passed as a parameter or redirected to via an HTTP redirect (CVE-2021-33503).

The urllib3 library 1.26.x before 1.26.4 for Python omits SSL certificate validation in some cases involving HTTPS to HTTPS proxies. The initial connection to the HTTPS proxy (if an SSLContext isn't given via proxy_config) doesn't verify the hostname of the certificate. This means certificates for different servers that still validate properly with the default urllib3 SSLContext will be silently accepted (CVE-2021-28363).

An issue was discovered in urllib3 before 1.26.5. When provided with a URL containing many @ characters in the authority component, the authority regular expression exhibits catastrophic backtracking, causing a denial of service if a URL were passed as a parameter or redirected to via an HTTP redirect (CVE-2021-33503).

This update for python-urllib3 fixes the following issues:

• CVE-2021-33503: Fixed a denial of service when the URL contained many @ characters in the authority component (bsc#1187045)

These are all security issues fixed in the python36-urllib3-1.26.6-1.2 package on the GA media of openSUSE Tumbleweed.

These are all security issues fixed in the python310-urllib3_1-1.26.15-1.1 package on the GA media of openSUSE Tumbleweed.

These are all security issues fixed in the python310-urllib3-2.1.0-3.1 package on the GA media of openSUSE Tumbleweed.

These are all security issues fixed in the python313-urllib3-2.8.0-1.1 package on the GA media of openSUSE Tumbleweed.

These are all security issues fixed in the python313-urllib3_1-1.26.20-7.2 package on the GA media of openSUSE Tumbleweed.

An issue was discovered in urllib3 before 1.26.5. When provided with a URL containing many @ characters in the authority component, the authority regular expression exhibits catastrophic backtracking, causing a denial of service if a URL were passed as a parameter or redirected to via an HTTP redirect.

Root has patched CVE-2021-33503 in the rootio-urllib3 package for Root:PyPI. Multiple fixed versions available.

This feature update for venv-salt-minion provides the following changes:

• Introduce venv-salt-minion.
• Track already fixed issues.

This feature update for venv-salt-minion provides the following changes:

• Introduce venv-salt-minion.
• Mention fixed issues provided with the bundle.

This update for the SLE Public Cloud module provides the following fixes:

Azure SDK update: This update for the Azure SDK and CLI adds support for the AHB (Azure Hybrid Benefit). (bsc#1176784, jsc#ECO-3105)

AWS SDK update: This update for the AWS SDK updates python-boto3 to version 1.17.9 and aws-cli to 1.19.9. (bsc#1182421, jsc#ECO-3352)

Security fix for python-urllib3:

• Improve performance of sub-authority splitting in URL. (bsc#1187045, CVE-2021-33503)

This update for python-urllib3 fixes the following issues:

• CVE-2021-33503: Fixed a denial of service when the URL contained many @ characters in the authority component (bsc#1187045)

This update for python-urllib3 and python-requests fixes the following issues:

Security fix:

• Improve performance of sub-authority splitting in URL. (bsc#1187045, CVE-2021-33503)

Non-security changes:

• Update python-urllib3 to version 1.25.10 to stay compatible with changes needed in the Server and Public Cloud products. (bsc#1182421, jsc#ECO-3352)
• Update python-requests to version 2.24.0 to stay compatible with changes needed in the Server and Public Cloud products. (bsc#1176784, jsc#ECO-3105))

It was discovered that urllib3 incorrectly handled certain characters in URLs. A remote attacker could possibly use this issue to cause urllib3 to consume resources, leading to a denial of service.