CVE Tools
Sign in

CVE-2021-3517

Published: May 19, 2021Updated: Dec 2, 2025 Sources: CVE List NVD GHSA BDU csafCWE-787
NVD MITRE
8.6CVSSHIGH
EPSS Score
8.3%
Top 5.8%
CISA KEV
Not in KEV
Exploits
1 Known
Remediation
Patch Available

Description

There is a flaw in the xml entity encoding functionality of libxml2 in versions before 2.9.11. An attacker who is able to supply a crafted file to be processed by an application linked with the affected functionality of libxml2 could trigger an out-of-bounds read. 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.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:LI:LA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:LConfidentiality
Low
I:LIntegrity
Low
A:HAvailability
High
Open in CVSS calculator →

Weaknesses

CWE-787CWE-125

Affected Products

Debian GNU/LinuxСообщество свободного программного обеспечения
On-premOS
Operating Systems / linux-distro
Astra Linux Special EditionООО «РусБИТех-Астра»
On-premOS
Operating Systems / linux-distro
Astra Linux Special Edition для «Эльбрус»ООО «РусБИТех-Астра»
On-premOS
Operating Systems / linux-distro
libxml2Сообщество свободного программного обеспечения
LibraryLibrary
OSS Libraries / generic-library
ОС ОН «Стрелец»АО «Концерн ВНИИНС»
On-premOS
Operating Systems / linux-distro
сообщество свободного программного обеспеченияoss-projectOperating Systemsaka сообщество свободного программного обеспечения, fsf
ооо «русбитех-астра»commercialRUOperating Systemsaka rusbitech-astra
ао «концерн вниинс»commercialRUOperating Systemsaka ao konsern vniins
and 33 more affected products View all →

Attack Graph

Products CVE Techniques Tactics

Click technique nodes to view MITRE ATT&CK details. Scroll to zoom, drag to pan.

Exploitability

1 exploit source identified

Exploit details including PoC links, Metasploit modules, and scanner templates are available after registration.

View exploit details
Official Patch Available

MITRE ATT&CK

3 techniques
Collection
Initial Access
Privilege Escalation
View detailed technique mapping

References

https://gitlab.gnome.org/GNOME/libxml2/-/commit/bf22713507fe1fc3a2c4b525cf0a88c2dc87a3a2
gitlab.gnome.org
https://gitlab.gnome.org/GNOME/libxml2/-/issues/235
gitlab.gnome.org
https://nvd.nist.gov/vuln/detail/CVE-2021-3517
nvd.nist.gov
and 44 more references View all →

Timeline

Published
May 19, 2021
Last Updated
Dec 2, 2025

Unlock Complete Vulnerability Intelligence

Get the full picture for CVE-2021-3517 and every CVE in our database. Create a free account — no credit card required.

Create Free Account
Plain-language analysis
Impact assessment and exploitation scenario in plain English
Attack graph visualization
Interactive attack path and kill chain mapping
Exploit details & PoC links
ExploitDB, Metasploit, GitHub PoCs with direct links
Nuclei scanner templates
Ready-to-use vulnerability scanner templates
Full remediation guide
Patch instructions, workarounds, and compliance impact
Interactive AI chat
Ask questions about this vulnerability in natural language
Related vulnerabilities
Semantically similar CVEs and attack patterns
REST API & MCP access
Integrate vulnerability data into your workflows