CVE-2021-33503
Apache HTTP Server URL Parsing Denial of Service
Description
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.
INFO
Published Date :
June 29, 2021, 11:15 a.m.
Last Modified :
Nov. 7, 2023, 3:35 a.m.
Source :
[email protected]
Remotely Exploitable :
Yes !
Impact Score :
3.6
Exploitability Score :
3.9
Public PoC/Exploit Available at Github
CVE-2021-33503 has a 3 public PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
Affected Products
The following products are affected by CVE-2021-33503
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-33503.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
CMake Shell Perl C++ C Batchfile CSS Makefile M4 Python
A tool to analyse the list of detected CVEs in the containers (usually created by static security scanner) and compare them to the Red Hat Security Data.
security openshift
Go Makefile
List of RegEx DoS (ReDoS) CVEs and resources
security awesome redos regex dos regex-dos pentesting awesome-list regex-security
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-33503 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-33503 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
CVE Modified by [email protected]
Nov. 07, 2023
Action Type Old Value New Value Added Reference MITRE https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FMUGWEAUYGGHTPPXT6YBD53WYXQGVV73/ [No types assigned] Added Reference MITRE https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6SCV7ZNAHS3E6PBFLJGENCDRDRWRZZ6W/ [No types assigned] Removed Reference MITRE https://lists.fedoraproject.org/archives/list/[email protected]/message/FMUGWEAUYGGHTPPXT6YBD53WYXQGVV73/ Removed Reference MITRE https://lists.fedoraproject.org/archives/list/[email protected]/message/6SCV7ZNAHS3E6PBFLJGENCDRDRWRZZ6W/ -
Reanalysis by [email protected]
Aug. 24, 2023
Action Type Old Value New Value Changed CPE Configuration OR *cpe:2.3:a:python:urllib3:*:*:*:*:*:*:*:* versions up to (excluding) 1.25.4 *cpe:2.3:a:python:urllib3:*:*:*:*:*:*:*:* versions from (including) 1.26.0 up to (excluding) 1.26.5 OR *cpe:2.3:a:python:urllib3:*:*:*:*:*:*:*:* versions from (including) 1.25.4 up to (excluding) 1.26.5 -
Reanalysis by [email protected]
Jan. 24, 2023
Action Type Old Value New Value Changed CPE Configuration OR *cpe:2.3:a:python:urllib3:*:*:*:*:*:*:*:* versions up to (excluding) 1.26.5 OR *cpe:2.3:a:python:urllib3:*:*:*:*:*:*:*:* versions up to (excluding) 1.25.4 *cpe:2.3:a:python:urllib3:*:*:*:*:*:*:*:* versions from (including) 1.26.0 up to (excluding) 1.26.5 -
Modified Analysis by [email protected]
Dec. 08, 2021
Action Type Old Value New Value Changed Reference Type https://www.oracle.com/security-alerts/cpuoct2021.html No Types Assigned https://www.oracle.com/security-alerts/cpuoct2021.html Patch, Third Party Advisory Added CPE Configuration OR *cpe:2.3:a:oracle:enterprise_manager_ops_center:12.4.0.0:*:*:*:*:*:*:* *cpe:2.3:a:oracle:instantis_enterprisetrack:17.1:*:*:*:*:*:*:* *cpe:2.3:a:oracle:instantis_enterprisetrack:17.2:*:*:*:*:*:*:* *cpe:2.3:a:oracle:instantis_enterprisetrack:17.3:*:*:*:*:*:*:* *cpe:2.3:a:oracle:zfs_storage_appliance_kit:8.8:*:*:*:*:*:*:* -
CVE Modified by [email protected]
Oct. 20, 2021
Action Type Old Value New Value Added Reference https://www.oracle.com/security-alerts/cpuoct2021.html [No Types Assigned] -
Modified Analysis by [email protected]
Sep. 14, 2021
Action Type Old Value New Value Changed Reference Type https://lists.fedoraproject.org/archives/list/[email protected]/message/6SCV7ZNAHS3E6PBFLJGENCDRDRWRZZ6W/ No Types Assigned https://lists.fedoraproject.org/archives/list/[email protected]/message/6SCV7ZNAHS3E6PBFLJGENCDRDRWRZZ6W/ Mailing List, Third Party Advisory Changed Reference Type https://lists.fedoraproject.org/archives/list/[email protected]/message/FMUGWEAUYGGHTPPXT6YBD53WYXQGVV73/ No Types Assigned https://lists.fedoraproject.org/archives/list/[email protected]/message/FMUGWEAUYGGHTPPXT6YBD53WYXQGVV73/ Mailing List, Third Party Advisory Changed Reference Type https://security.gentoo.org/glsa/202107-36 No Types Assigned https://security.gentoo.org/glsa/202107-36 Third Party Advisory Added CPE Configuration OR *cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* *cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* -
CVE Modified by [email protected]
Jul. 15, 2021
Action Type Old Value New Value Added Reference https://security.gentoo.org/glsa/202107-36 [No Types Assigned] -
CVE Modified by [email protected]
Jul. 08, 2021
Action Type Old Value New Value Added Reference https://lists.fedoraproject.org/archives/list/[email protected]/message/6SCV7ZNAHS3E6PBFLJGENCDRDRWRZZ6W/ [No Types Assigned] -
CVE Modified by [email protected]
Jul. 04, 2021
Action Type Old Value New Value Added Reference https://lists.fedoraproject.org/archives/list/[email protected]/message/FMUGWEAUYGGHTPPXT6YBD53WYXQGVV73/ [No Types Assigned] -
Initial Analysis by [email protected]
Jul. 02, 2021
Action Type Old Value New Value Added CVSS V2 NIST (AV:N/AC:L/Au:N/C:N/I:N/A:P) Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Changed Reference Type https://github.com/advisories/GHSA-q2q7-5pp4-w6pg No Types Assigned https://github.com/advisories/GHSA-q2q7-5pp4-w6pg Third Party Advisory Changed Reference Type https://github.com/urllib3/urllib3/commit/2d4a3fee6de2fa45eb82169361918f759269b4ec No Types Assigned https://github.com/urllib3/urllib3/commit/2d4a3fee6de2fa45eb82169361918f759269b4ec Patch, Third Party Advisory Added CWE NIST CWE-400 Added CPE Configuration OR *cpe:2.3:a:python:urllib3:*:*:*:*:*:*:*:* versions up to (excluding) 1.26.5
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-33503 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-33503
weaknesses.
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
0.29 }} 0.04%
score
0.68486
percentile