CVE-2021-3517

highpriority · track · 40EPSS 0.170 · 97 %ileDEEURUUS
grimoire priorityP1 · Urgent
Exploitable?
—
no known exploitation
Likely / severe?
17.0% (97th) EPSS
CVSS 7.5 · high
Is it mine?
86 products
Check your exposure
Who says so?
9 sources
cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-22

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.

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

02

cvss

Technical severity, 0–10. One row per scoring source.

8.6
010

base score 0–10 · higher = more severe · hover a vector to decode

v2.07.5highAV:N/AC:L/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 10 · impact 6.4
v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 4.7
v3.08.6highCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:Hsecondary · CISA US
v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:Hsecondary · ENISA EU
v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:Hsecondaryexploitability 3.9 · impact 4.7
v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:Hsecondary · OSV
v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H/E:P/RL:O/RC:Csecondary · Siemens ProductCERT DE
v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:Hsecondary · Phoenix Contact PSIRT DE
v3.17.9highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H/E:Usecondary · CVSS-BT (t0sche)
v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:Hsecondary · SUSE Product Security
v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H/E:P/RL:O/RC:Csecondary · CISA US
v3.18.6highAV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:Hsecondary · FSTEC (BDU) RU
03

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS
04

weaknesses

The CWE weakness classes this flaw belongs to.

05

affected products (86)

Products and version ranges known to be affected.

06

advisories (11)

Vendor and ecosystem advisories describing this.

  • SSA-398330SSA-398330: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP >= V3.1.0 and < V3.1.52023-12-12csaf · siemens_psirtDE

    Multiple vulnerabilities have been identified in the additional GNU/Linux subsystem of the firmware version >= V3.1.0 and < V3.1.5 for the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP (incl. SIPLUS variant). These GNU/Linux vulnerabilities have been externally identified. Siemens has released new versions for the affected products and recommends to update to the latest versions. SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP >= V3.1.0 and < V3.1.5 are no longer maintained and there won't be any update to the CVE list anymore. Please update to the latest version. Note: This SSA advises vulnerabilities for firmware version V3.1 only; for versions < V3.1 refer to Siemens Security Bulletin SSB-439005 (https://cert-portal.siemens.com/productcert/html/ssb-439005.html).

  • VDE-2022-010PHOENIX CONTACT: Multiple Linux component vulnerabilities fixed in latest AXC F x152 LTS release2022-04-12csaf · phoenix_contact_psirtDE

    PLCnext Control AXC F x152 is certified according to IEC 62443-4-1 and IEC 62443-4-2. This certification requires that all third-party components used in the firmware are regularly checked for known vulnerabilities. Firmware components in version 2021.06 had already been updated. For the 2022.0 LTS version more firmware components have been updated implicitly fixing the vulnerabilities listed. The vulnerabilities listed above have not been individually verified in terms of actual impact and/or limitations in combination with the affected products listed. The current LTS release 2022.0 LTS contains updates of integrated third-party libraries, SDKs and other third-party software to address these issues nevertheless. UPDATE A (April 4th, 2022): Added RFC 4072 (Art. No. 1051328) and fixed affected version of AXC F 3152

  • WID-SEC-W-2022-0196Oracle Java SE: Mehrere SchwachstellenDeutsch2021-10-19csaf · cert_bundDE

    Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Oracle Java SE ausnutzen, um die Vertraulichkeit, Integrität und Verfügbarkeit zu gefährden.

  • WID-SEC-W-2023-0395Splunk Splunk Enterprise: Mehrere SchwachstellenDeutsch2023-02-14csaf · cert_bundDE

    Ein Angreifer kann mehrere Schwachstellen in Splunk Splunk Enterprise ausnutzen, um vertrauliche Informationen offenzulegen, Sicherheitsmaßnahmen zu umgehen, einen Denial-of-Service-Zustand zu verursachen, Daten zu manipulieren und einen Cross-Site-Scripting-Angriff durchzuführen.

  • WID-SEC-W-2023-1152libxml2: Mehrere Schwachstellen ermöglichen nicht spezifizierten AngriffDeutsch2021-04-27csaf · cert_bundDE

    Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in libxml2 ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen.

  • WID-SEC-W-2023-1614Tenable Security Nessus Network Monitor: Mehrere SchwachstellenDeutsch2023-06-29csaf · cert_bundDE

    Ein entfernter, anonymer, authentisierter oder lokaler Angreifer kann mehrere Schwachstellen in Tenable Security Nessus Network Monitor ausnutzen, um beliebigen Code auszuführen, vertrauliche Informationen offenzulegen, einen Denial-of-Service-Zustand auszulösen und Daten zu manipulieren.

  • openSUSE-SU-2026:10356-1ruby4.0-rubygem-nokogiri-1.18.9-1.4 on GA media2026-03-13csaf · suse_csafDE

    ruby4.0-rubygem-nokogiri-1.18.9-1.4 on GA media

  • GHSA-jw9f-hh49-cvp9Nokogiri contains libxml Out-of-bounds Write vulnerability2022-05-24ghsa · osvUS

    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. Nokogiri prior to version 1.11.4 used a vulnerable version of libxml2. Nokogiri 1.11.4 updated libxml2 to version 2.9.11 to address this and other vulnerabilities in libxml2.

  • ICSA-21-336-06Hitachi Energy APM Edge2021-12-02icsa · cisa_csaf_otUS

    Successful exploitation of this vulnerability could cause the product to become inaccessible.

  • ICSA-21-336-08Hitachi Energy RTU500 series2021-12-02icsa · cisa_csaf_otUS

    Successful exploitation of these vulnerabilities could allow an attacker to eavesdrop on traffic, retrieve information from memory, or cause a denial-of-service condition.

  • ICSA-23-348-10Siemens SIMATIC S7-15002023-12-12icsa · cisa_csaf_otUS

    Multiple vulnerabilities have been identified in the additional GNU/Linux subsystem of the firmware version >= V3.1.0 and < V3.1.5 for the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP (incl. SIPLUS variant). These GNU/Linux vulnerabilities have been externally identified. Siemens has released new versions for the affected products and recommends to update to the latest versions. Note: This SSA advises vulnerabilities for firmware version V3.1 only; for versions < V3.1 refer to Siemens Security Bulletin SSB-439005 ( https://cert-portal.siemens.com/productcert/html/ssb-439005.html).

07

also known as (4)

Other names and identifiers for this entity.

08

sources

Which sources assert this record, and when.

09

references (74)

External citations — patches, advisories, analysis.

scry

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