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CVE-2016-1838

Published: May 20, 2016Updated: May 6, 2026 Sources: CVE List NVD BDUCWE-125
5.5MEDIUM
NVD MITRE
EPSS Score
6.9%
Top 6.3%
CISA KEV
Not in KEV
Exploits
2 Known
Remediation
Patch Available
Self-Check
OpenVAS

Description

The xmlPArserPrintFileContextInternal function in libxml2 before 2.9.4, as used in Apple iOS before 9.3.2, OS X before 10.11.5, tvOS before 9.2.1, and watchOS before 2.2.1, allows remote attackers to cause a denial of service (heap-based buffer over-read) via a crafted XML document.

In plain language

AI Worth attention

This bug is in an XML-reading feature and can be triggered by opening a specially crafted XML file to crash or freeze affected Apple devices; if your business devices aren’t updated to the listed versions, you should act.

Executive summary

CVE-2016-1838 is a heap-based buffer over-read in the xmlPArserPrintFileContextInternal function in libxml2 (before 2.9.4) as used by Apple iOS/tvOS/watchOS/macOS; it is triggered when a user opens a crafted XML document, leading to a denial of service (crash/unresponsiveness) rather than data theft.

If affected, business impact
Device or service disruptionWorkflow downtimePotential forced restartsReduced availability risk

What to do now

  1. Check whether any business-owned Apple devices (iOS, macOS/OS X, tvOS, watchOS) and any apps that include/ship libxml2 are on versions older than iOS 9.3.2, OS X 10.11.5, tvOS 9.2.1, or watchOS 2.2.1.
  2. Update iOS devices to 9.3.2 or newer.
  3. Update macOS/OS X devices to 10.11.5 or newer.
  4. Update tvOS devices to 9.2.1 or newer.
  5. Update watchOS devices to 2.2.1 or newer.
  6. If immediate updating isn’t possible, restrict users from opening XML files from unknown sources and block unexpected XML attachments coming from email/web downloads.
Patch / advisory Usually a quick update

CVSS Vector Breakdown

AV:LAC:LPR:NUI:RS:UC:NI:NA:H
Exploitability
AV:LAttack Vector
Local
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:RUser Interaction
Required
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
Open in CVSS calculator →

Weaknesses

CWE-125

Affected Products

Apple Inc.
commercial·USaka apple, apple computer
iOSEmbeddedOS
Operating Systems / mobile-os
mac os xOn-premOS
Operating Systems / unix-bsd
tvosEmbeddedOS
Operating Systems / mobile-os
watchosEmbeddedOS
Operating Systems / mobile-os
OS X
Operating Systems
Canonical Ltd.
commercial·GBaka canonical
UbuntuOn-premOS
Operating Systems / linux-distro
debian
oss-project·GBaka debian gnu/linux
debian linuxOn-premOS
Operating Systems / linux-distro
Red Hat Inc.
commercial·USaka redhat, red hat
Red Hat Enterprise Linux ServerOn-premOS
Operating Systems / linux-distro
mcafee
commercial·USaka mcaee, mcafee security
web gateway
Security Products
xmlsoft
oss-projectaka libxml2, libxslt
libxml2LibraryLibrary
OSS Libraries / generic-library
and 12 more affected products View all →

Exploitability

2 exploit sources identified

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

View exploit details
Official Patch Available
Is your org exposed to CVE-2016-1838?We can run the check for you — a free external exposure review, no install. Check my exposure

Attack Graph

Products CVE Techniques Tactics

Click technique nodes for MITRE ATT&CK details · drag to pan · Ctrl/⌘ + scroll to zoom, or go fullscreen.

MITRE ATT&CK

1 technique
Collection
View detailed technique mapping

References

http://lists.apple.com/archives/security-announce/2016/May/msg00001.html
lists.apple.com
http://lists.apple.com/archives/security-announce/2016/May/msg00002.html
lists.apple.com
http://lists.apple.com/archives/security-announce/2016/May/msg00003.html
lists.apple.com
and 35 more references View all →

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