Staging Environment: Content and features may be unstable or change without notice.
Advisory details: gitlab / nuget/libxml2/CVE-2021-3517
Advisory ID gitlab/nuget/libxml2/CVE-2021-3517
Aliases CVE-2021-3517
Summary Out-of-bounds Write There is a flaw in the xml entity encoding functionality of libxml2 The most likely impact of this flaw is to application availability, with some potential impact to confidentiality and integrity if an attacker is able to use memory information to further exploit the application.
Status Published
Exploitability 0.5
Weighted Severity 0.0
Risk
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (3)
CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
CWE-787 Out-of-bounds Write
CWE-937 OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities
System Score Found at
cvssv2 https://gitlab.com/gitlab-org/advisories-community/-/blob/main/nuget/libxml2/CVE-2021-3517.yml
cvssv3.1 https://gitlab.com/gitlab-org/advisories-community/-/blob/main/nuget/libxml2/CVE-2021-3517.yml
Reference id Reference type URL
https://bugzilla.redhat.com/show_bug.cgi?id=1954232
CVE-2021-3517 https://nvd.nist.gov/vuln/detail/CVE-2021-3517
No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
Vector: AV:N/AC:L/Au:N/C:P/I:P/A:P Found at https://gitlab.com/gitlab-org/advisories-community/-/blob/main/nuget/libxml2/CVE-2021-3517.yml
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

partial

complete

none

partial

complete
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H Found at https://gitlab.com/gitlab-org/advisories-community/-/blob/main/nuget/libxml2/CVE-2021-3517.yml
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: SSVCv2/E:N/A:Y/T:P/P:M/B:A/M:M/D:T/2025-12-02T21:32:30Z/

Decision: Track

Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2021/3xxx/CVE-2021-3517.json

Source Advisory: vulnrichment/CVE-2021-3517

View SSVC decision tree 
[{'Exploitation': 'none'},
 {'Automatable': 'yes'},
 {'Technical Impact': 'partial'},
 {'Mission Prevalence': 'minimal'},
 {'Public Well-being Impact': 'material'},
 {'Mission & Well-being': 'medium'}]