dbcve.org
Ubuntu LinuxOperating system · Canonical

CVE-2016-4353

HIGH · 7.5 CVSS v3.0 Published 2016-06-13
Fix available
A fix is available. Upgrade to after 1.3.2 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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
ber-decoder.c in Libksba before 1.3.3 does not properly handle decoder stack overflows, which allows remote attackers to cause a denial of service (abort) via crafted BER data.

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

The ber-decoder.c component in Libksba versions before 1.3.3 contains a stack overflow vulnerability in its BER (Basic Encoding Rules) decoder. The decoder fails to properly validate or handle malformed BER data, allowing remote attackers to trigger stack overflow conditions via crafted malicious BER input, resulting in denial of service (process abort).

MitigationUpgrade Libksba to version 1.3.3 or later to obtain the patched ber-decoder.c component. If immediate upgrading is not feasible, consider input validation or network-level filtering of BER data from untrusted sources.

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
LibksbaApplication
Affected:<= 1.3.2

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
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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. Identify if Libksba is installed
    Run 'dpkg -l | grep libksba' on Debian/Ubuntu systems, or 'rpm -qa | grep ksba' on Red Hat-based systems. On other systems, check for the presence of libksba shared libraries in /usr/lib or via 'ldconfig -p | grep ksba'.
    Affected if Libksba is found installed on the system
  2. Determine the installed Libksba version
    Run 'dpkg -l libksba' (Debian/Ubuntu) or 'rpm -q libksba' (Red Hat) to retrieve the exact version number. Alternatively, check /usr/share/doc/libksba/ or use 'ksba-config --version' if available.
    Affected if The installed version is 1.3.2 or earlier, or the version cannot be determined (older than 1.3.3)
  3. Check if the ber-decoder component is in use
    Identify processes that link against libksba by running 'lsof | grep libksba' or checking application dependencies. Applications using GnuPG or any tool that handles X.509 certificates may load this library.
    Affected if Any application using Libksba's BER decoder functionality is running or configured
  4. Identify the operating system version on Ubuntu
    Run 'lsb_release -a' or check /etc/lsb-release to confirm the Ubuntu version. Also check /etc/apt/sources.list for installed Libksba packages.
    Affected if Running Ubuntu 12.04 or Ubuntu 14.04 with Libksba installed
  5. Verify the ber-decoder.c component version
    If the library source is present, check the file version in ber-decoder.c header comments. Otherwise, check the shared library version using 'objdump -x /usr/lib/libksba.so.* | grep VERSION' or 'readelf -d /usr/lib/libksba.so.* | grep VERSION'.
    Affected if The library file shows version 1.3.2 or earlier, or the ber-decoder component cannot be verified as 1.3.3 or later

The system is affected if Libksba version 1.3.2 or earlier (or an unknown version on Ubuntu 12.04/14.04) is installed and any application uses the BER decoder functionality.

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 1.3.2
Interim mitigation

Upgrade Libksba to version 1.3.3 or later to obtain the patched ber-decoder.c component. If immediate upgrading is not feasible, consider input validation or network-level filtering of BER data from untrusted sources.

Fix this in Ubuntu Linux Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,080
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,328.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2016-4353 — 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-2016-4353 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