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Fencer Vulns
high 7.5

CVE-2017-9233 json

XML External Entity vulnerability in libexpat 2.2.0 and earlier (Expat XML Parser Library) allows attackers to put the parser in an infinit…

published 2017-07-25 9 y ago modified 2026-10-08 31 d ago also EUVD-2017-18171

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
8.7%
EPSS 8.7% chance of exploitation in 30 days, percentile 95%
public exploits
0
none known

Summary

XML External Entity vulnerability in libexpat 2.2.0 and earlier (Expat XML Parser Library) allows attackers to put the parser in an infinite loop using a malformed external entity definition from an external DTD.

Patch / fix

  • python python 2.7.15, 3.3.7, 3.4.7, 3.5.4, 3.6.2
  • expat Debian 14, Debian 13, Debian 12 2.2.1-1

debian advisories DEBIAN-CVE-2017-9233

  • expat Ubuntu 14.04 LTS 2.1.0-4ubuntu1.4
  • expat Ubuntu 16.04 LTS 2.1.0-7ubuntu0.16.04.3
  • coin3 Ubuntu Pro 14.04 LTS 3.1.4~abc9f50-4ubuntu2+esm1
  • coin3 Ubuntu Pro 16.04 LTS 3.1.4~abc9f50+dfsg1-1ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2017-9233

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • python3 SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +18 more 3.4.10-25.39.3
  • python3-base SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +18 more 3.4.10-25.39.2
  • expat Studio Onsite 1.3, SLES for SAP 11 SP4, SLES 11 SP4 +1 more 2.0.1-88.42.3.2
  • expat SLES for SAP 12 SP3, SLES for SAP 12 SP2, SLES for Raspberry Pi 12 SP2 +6 more 2.1.0-21.3.1

suse advisories SUSE-SU-2020:0497-1SUSE-SU-2017:2375-1SUSE-SU-2017:2299-1

  • expat openSUSE Tumbleweed 2.4.1-1.2

opensuse advisories openSUSE-SU-2024:10748-1

  • expat Alpine 3.24, Alpine 3.23, Alpine 3.22 +18 more 2.2.0-r1

alpine advisories ALPINE-CVE-2017-9233

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • lib32-expat Arch Linux 2.2.2-1
  • expat Arch Linux 2.2.1-1

arch linux advisories AVG-305AVG-306

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2017-9233 updated cvss 7.5

expat: Inifinite loop due to invalid XML in external entity

  • Red Hat Enterprise Linux 5 expat, firefox, xmlrpc-c, xulrunner, thunderbird Red Hat Enterprise Linux 6 firefox, xulrunner, thunderbird, compat-expat1 Red Hat Enterprise Linux 7 expat, firefox, xulrunner, thunderbird Red Hat Enterprise Virtualization 3 mingw-virt-viewer, mingw32-virt-viewer, mingw64-virt-viewer Red Hat JBoss Enterprise Application Platform 6 httpd, mod_ssl, mod_ldap, httpd-tools, httpd-manual Red Hat JBoss Enterprise Web Server 2 jbcs-httpd24, jbcs-httpd24-runtime
    affected: workaround, no fix planned “Do not parse untrusted arbitrary XML data using the expat package.”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

cisa ICSA-19-155-01 updated cvss 7.5

PHOENIX CONTACT PLCNext AXC F 2152

  • Phoenix Contact AXC F 2152 2404267 version 1.x, 1046568 (Starterkit) version 1.x
    affected: vendor fix, mitigation “Phoenix Contact recommends affected users update to firmware release 2019.0 LTS or later, update to PLCNext Engineer release 2019.0 LTS or later, and apply the following specific mitigations below:” phoenixcontact.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
31 d ago

Exploit prediction

8.74% chance of exploitation in the next 30 days, higher than 95% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • libexpat.github.io https://libexpat.github.io/doc/cve-2017-9233/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Classification

Weakness
  • CWE-611 Improper Restriction of XML External Entity Reference
  • CWE-835 Loop with Unreachable Exit Condition

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.