dbcve.org
Ubuntu LinuxOperating system · Canonical

CVE-2016-1835

HIGH · 8.8 CVSS v3.0 Published 2016-05-20
Fix available
A fix is available. Upgrade to after 10.11.4 or later.
See remediation →
95/100
Remediation priority · Urgent
Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Use-after-free vulnerability in the xmlSAX2AttributeNs function in libxml2 before 2.9.4, as used in Apple iOS before 9.3.2 and OS X before 10.11.5, allows remote attackers to cause a denial of service via a crafted XML document.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A use-after-free vulnerability exists in the xmlSAX2AttributeNs function of libxml2 versions prior to 2.9.4. When processing crafted XML documents, the parser improperly handles memory allocation/deallocation, allowing a remote attacker to reference freed memory and potentially execute arbitrary code or cause denial of service.

MitigationUpgrade libxml2 to version 2.9.4 or later. For affected Apple systems, apply iOS 9.3.2+ and OS X 10.11.5+ security updates which include the patched libxml2 library.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Ubuntu LinuxOperating system
Affected:= 12.04= 14.04= 15.10= 16.04
Debian LinuxOperating system
Affected:= 8.0
Iphone OsOperating system
Affected:<= 9.3.1
Mac Os XOperating system
Affected:<= 10.11.4

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check libxml2 version on Ubuntu/Debian
    Run `dpkg -l libxml2` or `apt show libxml2` to see the installed version
    Affected if The displayed version is earlier than 2.9.4 (e.g., 2.9.3, 2.9.2, etc.)
  2. Check libxml2 library file version directly
    Run `xml2 --version` or check the shared library with `ls -l /usr/lib/x86_64-linux-gnu/libxml2.so*` and use `strings` or `objdump -p` to find the version embedded in the binary
    Affected if The library version reported is before 2.9.4
  3. Check if using RPM-based Linux
    Run `rpm -q libxml2` to query the installed package
    Affected if The version returned is less than 2.9.4
  4. Check Apple iOS version
    On the iOS device, go to Settings > General > About and check the Version number
    Affected if The iOS version is 9.3.1 or earlier (the device likely has the vulnerable libxml2)
  5. Check Apple macOS version
    Click the Apple menu > About This Mac to view the OS X/macOS version
    Affected if The Mac OS X version is 10.11.4 or earlier (the system likely has the vulnerable libxml2)

A system is affected if it runs libxml2 with a version lower than 2.9.4, or if it is an Apple device running iOS 9.3.1 or earlier or OS X 10.11.4 or earlier.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to a release after 10.11.4
Interim mitigation

Upgrade libxml2 to version 2.9.4 or later. For affected Apple systems, apply iOS 9.3.2+ and OS X 10.11.5+ security updates which include the patched libxml2 library.

Fix this in Ubuntu Linux Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
15.0 hours of engineering $2,640
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,224.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2016-1835 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2016-1835 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data