Ubuntu LinuxOperating system · Canonical
CVE-2016-4355
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 · uneditedMultiple integer overflows in ber-decoder.c in Libksba before 1.3.3 allow remote attackers to cause a denial of service (crash) via crafted BER data, which leads to a buffer overflow.
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 confidenceLibksba before version 1.3.3 contains multiple integer overflow vulnerabilities in ber-decoder.c when parsing BER (Basic Encoding Rules) data. These overflows allow remote attackers to trigger buffer overflows via crafted BER input, causing denial of service via crash.
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
= 12.04= 14.04<= 1.3.2CVSS 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 checksWork through these to decide whether this CVE applies to you.
-
Identify installed Libksba versionRun 'dpkg -l libksba' on Debian/Ubuntu systems, or 'rpm -q libksba' on RHEL/CentOS systems, or check the library file version with 'ksba-config --version' if the tool is installedAffected if The version shown is 1.3.2 or earlier, or the package is not found but the library is in use by other applications
-
Check Ubuntu distribution versionRun 'lsb_release -r' or check '/etc/lsb-release' to identify the Ubuntu versionAffected if The system runs Ubuntu 12.04 or Ubuntu 14.04 and has libksba installed
-
Verify ber-decoder component existsCheck for the presence of libksba library files: locate 'libksba.so*' in /usr/lib/ or run 'ldconfig -p | grep ksba' to list loaded ksba librariesAffected if The libksba library is present on the system (indicating the vulnerable component is installed)
-
Confirm application dependency on LibksbaCheck which applications use libksba by running 'ldd' on GnuPG-related binaries or searching for 'libksba' in process memory if applicableAffected if Applications that handle certificate or cryptographic operations depend on libksba and the library version is <= 1.3.2
If Libksba version 1.3.2 or earlier is installed, or Ubuntu 12.04/14.04 with Libksba is in use, the system is vulnerable to integer overflows in ber-decoder.c leading to potential denial of service.
Generated from the published advisory. Verify against your own configuration.
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 dataUpgrade Libksba to version 1.3.3 or later to patch the integer overflow vulnerabilities. If upgrade is not immediately feasible, input validation and filtering of BER data before processing can provide temporary mitigation.
Fix this in Ubuntu Linux
Scoped from the published advisory
- Consultation2.0 h
- Implementation2.0 h
- Testing4.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,464.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-4355 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2016-4355 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
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.
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.
- 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