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Vulnerability details: VCID-t7s4-p32t-byeg
Vulnerability ID VCID-t7s4-p32t-byeg
Aliases CVE-2020-7212
GHSA-hmv2-79q8-fv6g
PYSEC-2020-149
Summary Uncontrolled Resource Consumption in urllib3 The _encode_invalid_chars function in util/url.py in the urllib3 library 1.25.2 through 1.25.7 for Python allows a denial of service (CPU consumption) because of an inefficient algorithm. The percent_encodings array contains all matches of percent encodings. It is not deduplicated. For a URL of length N, the size of percent_encodings may be up to O(N). The next step (normalize existing percent-encoded bytes) also takes up to O(N) for each step, so the total time is O(N^2). If percent_encodings were deduplicated, the time to compute _encode_invalid_chars would be O(kN), where k is at most 484 ((10+6*2)^2).
Status Published
Exploitability None
Weighted Severity None
Risk None
Affected and Fixed Packages Package Details
Weaknesses (1)
CWE-400 Uncontrolled Resource Consumption
System Score Found at
epss 0.0046 https://api.first.org/data/v1/epss?cve=CVE-2020-7212
cvssv3.1 7.5 https://github.com/advisories/GHSA-hmv2-79q8-fv6g
generic_textual HIGH https://github.com/advisories/GHSA-hmv2-79q8-fv6g
cvssv3.1 7.5 https://github.com/pypa/advisory-database/tree/main/vulns/urllib3/PYSEC-2020-149.yaml
generic_textual HIGH https://github.com/pypa/advisory-database/tree/main/vulns/urllib3/PYSEC-2020-149.yaml
cvssv3.1 7.5 https://github.com/urllib3/urllib3
generic_textual HIGH https://github.com/urllib3/urllib3
cvssv3.1 7.5 https://github.com/urllib3/urllib3/blob/master/CHANGES.rst
generic_textual HIGH https://github.com/urllib3/urllib3/blob/master/CHANGES.rst
cvssv3.1 7.5 https://github.com/urllib3/urllib3/commit/a74c9cfbaed9f811e7563cfc3dce894928e0221a
generic_textual HIGH https://github.com/urllib3/urllib3/commit/a74c9cfbaed9f811e7563cfc3dce894928e0221a
cvssv2 7.8 https://nvd.nist.gov/vuln/detail/CVE-2020-7212
cvssv3.1 7.5 https://nvd.nist.gov/vuln/detail/CVE-2020-7212
generic_textual HIGH https://nvd.nist.gov/vuln/detail/CVE-2020-7212
cvssv3.1 7.5 https://pypi.org/project/urllib3/1.25.8
generic_textual HIGH https://pypi.org/project/urllib3/1.25.8
Reference id Reference type URL
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2020-7212.json
https://api.first.org/data/v1/epss?cve=CVE-2020-7212
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-7212
https://github.com/advisories/GHSA-hmv2-79q8-fv6g
https://github.com/pypa/advisory-database/tree/main/vulns/urllib3/PYSEC-2020-149.yaml
https://github.com/urllib3/urllib3
https://github.com/urllib3/urllib3/blob/master/CHANGES.rst
https://github.com/urllib3/urllib3/commit/a74c9cfbaed9f811e7563cfc3dce894928e0221a
https://nvd.nist.gov/vuln/detail/CVE-2020-7212
https://pypi.org/project/urllib3/1.25.8
https://pypi.org/project/urllib3/1.25.8/
1812095 https://bugzilla.redhat.com/show_bug.cgi?id=1812095
cpe:2.3:a:python:urllib3:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:python:urllib3:*:*:*:*:*:*:*:*
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://github.com/advisories/GHSA-hmv2-79q8-fv6g
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://github.com/pypa/advisory-database/tree/main/vulns/urllib3/PYSEC-2020-149.yaml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://github.com/urllib3/urllib3
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

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high

low

none

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low

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high

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Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://github.com/urllib3/urllib3/blob/master/CHANGES.rst
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

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low

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Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://github.com/urllib3/urllib3/commit/a74c9cfbaed9f811e7563cfc3dce894928e0221a
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

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low

none

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none
Vector: AV:N/AC:L/Au:N/C:N/I:N/A:C Found at https://nvd.nist.gov/vuln/detail/CVE-2020-7212
Exploitability (E) Access Vector (AV) Access Complexity (AC) Authentication (Au) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

high

functional

unproven

proof_of_concept

not_defined

local

adjacent_network

network

high

medium

low

multiple

single

none

none

partial

complete

none

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complete

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complete
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2020-7212
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

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none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://pypi.org/project/urllib3/1.25.8
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Exploit Prediction Scoring System (EPSS)
Percentile 0.63138
EPSS Score 0.0046
Published At June 30, 2025, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2025-07-01T12:17:55.261244+00:00 GithubOSV Importer Import https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/04/GHSA-hmv2-79q8-fv6g/GHSA-hmv2-79q8-fv6g.json 36.1.3