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Fencer Vulns
high 7.5

CVE-2017-9047 json

A buffer overflow was discovered in libxml2 20904-GITv2.9.4-16-g0741801.

published 2017-05-18 9 y ago modified 2026-10-14 26 d ago also EUVD-2017-17987

cvss
7.5
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.2%
EPSS 3.2% chance of exploitation in 30 days, percentile 88%
public exploits
0
none known

Summary

A buffer overflow was discovered in libxml2 20904-GITv2.9.4-16-g0741801. The function xmlSnprintfElementContent in valid.c is supposed to recursively dump the element content definition into a char buffer 'buf' of size 'size'. The variable len is assigned strlen(buf). If the content->type is XML_ELEMENT_CONTENT_ELEMENT, then (i) the content->prefix is appended to buf (if it actually fits) whereupon (ii) content->name is written to the buffer. However, the check for whether the content->name actually fits also uses 'len' rather than the updated buffer length strlen(buf). This allows us to write about "size" many bytes beyond the allocated memory. This vulnerability causes programs that use libxml2, such as PHP, to crash.

Patch / fix

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP V3.1.5
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP V3.1.5
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP V3.1.5
  • libxml2 Debian 14, Debian 13, Debian 12 2.9.4+dfsg1-3.1

debian advisories DEBIAN-CVE-2017-9047

  • libxml2 Ubuntu 14.04 LTS 2.9.1+dfsg1-3ubuntu4.10
  • libxml2 Ubuntu 16.04 LTS 2.9.3+dfsg1-1ubuntu0.3

ubuntu advisories UBUNTU-CVE-2017-9047

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

  • libxml2 SLES for SAP 11 SP4, SLES 11 SP4, SLES 11 SP3-TERADATA +3 more 2.7.6-0.69.1
  • libxml2-python SLES for SAP 11 SP4, SLES 11 SP4, SLES 11 SP3-TERADATA +2 more 2.7.6-0.69.3
  • libxml2 SLES for SAP 12 SP2, SLES for Raspberry Pi 12 SP2, SLES 12 SP2 +2 more 2.9.4-39.2
  • python-libxml2 SLES for SAP 12 SP2, SLES for Raspberry Pi 12 SP2, SLES 12 SP2 +1 more 2.9.4-39.2
  • libxml2 SLES for SAP 12 SP2, SLES for Raspberry Pi 12 SP2, SLES 12 SP2 +2 more 2.9.4-36.1
  • python-libxml2 SLES for SAP 12 SP2, SLES for Raspberry Pi 12 SP2, SLES 12 SP2 +1 more 2.9.4-36.1
  • libxml2 SLES for SAP 12 SP1, SLES for SAP 12, SLES 12-LTSS +1 more 2.9.1-26.15.1
  • python-libxml2 SLES for SAP 12 SP1, SLES for SAP 12, SLES 12-LTSS +1 more 2.9.1-26.15.1

suse advisories SUSE-SU-2017:1587-1SUSE-SU-2017:1557-1SUSE-SU-2017:1538-1SUSE-SU-2017:1454-1

  • libxml2 openSUSE Tumbleweed 2.9.12-1.2

opensuse advisories openSUSE-SU-2024:11016-1

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-2017-9047 updated cvss 7.5

libxml2: Buffer overflow in function xmlSnprintfElementContent

  • Red Hat Enterprise Linux 5 libxml2 Red Hat Enterprise Linux 6 libxml2, libxml2-python Red Hat Enterprise Linux 7 libxml2, libxml2-python
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux 8 mingw-libxml2, mingw32-libxml2, mingw64-libxml2 Red Hat JBoss Core Services libxml2
    affected: no fix available
  • Red Hat JBoss Enterprise Web Server 3 libxml2
    affected: no fix planned “Will not fix”
  • Red Hat JBoss Core Services
    fixed: vendor fix RHSA-2018:2486
  • Red Hat Enterprise Linux 8 libxml2, python3-libxml2
    not affected: vulnerable code not present

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-23-348-10 updated cvss 7.5

Siemens SIMATIC S7-1500

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= 3.1.0, < 3.1.5 Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= 3.1.0, < 3.1.5
    affected: fixed in V3.1.5, mitigation support.industry.siemens.com

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

Exploit prediction

3.16% chance of exploitation in the next 30 days, higher than 88% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • openwall.com http://www.openwall.com/lists/oss-security/2017/05/15/1 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.0 7.5 CVSS:3.0/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

Affected products

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP

Classification

Weakness
  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

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.