CVE-2021-33503

CWE-400 — Uncontrolled Resource ConsumptionCWE-8359 documents8 sources
Severity
7.5HIGH
EPSS
0.9%
top 24.93%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
5
Python Urllib3Fedoraproject FedoraOracle Enterprise Manager OPS Center+2 more
Timeline
PublishedJun 29
Latest updateJan 19

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.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitability: 3.9 | Impact: 3.6

Affected Packages6 packages

▶PyPIurllib31.25.4 — 1.26.5
▶NVDpython/urllib31.25.4 — 1.26.5
▶Debianpython-urllib3< 1.26.5-1~exp1+3
▶NVDoracle/instantis_enterprisetrack17.1, 17.2, 17.3+2

Also affects: Fedora 33, 34

Patches

Patch: github.com ↗Patch: www.oracle.com ↗Patch: github.com ↗

🔴Vulnerability Details

4
OSV
CVE-2021-33503: An issue was discovered in urllib3 before 1↗2021-06-29
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CVEList
CVE-2021-33503: An issue was discovered in urllib3 before 1↗2021-06-29
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OSV
Catastrophic backtracking in URL authority parser when passed URL containing many @ characters↗2021-06-01
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GHSA
Catastrophic backtracking in URL authority parser when passed URL containing many @ characters↗2021-06-01
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📋Vendor Advisories

4
Ubuntu
urllib3 vulnerability↗2023-01-19
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Microsoft
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 c↗2021-06-08
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Red Hat
python-urllib3: ReDoS in the parsing of authority part of URL↗2021-06-01
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Debian
CVE-2021-33503: python-urllib3 - An issue was discovered in urllib3 before 1.26.5. When provided with a URL conta...↗2021
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CVE-2021-33503 (HIGH CVSS 7.5) | An issue was discovered in urllib3 | cvebase.io